army compositions

[Fewrfreyut]

hi folks!

I've been playing hoi3 for a little over a year now, and I felt like sharing what I felt a good (albeit a bit supply/fuel heavy) offensive army is made of.

I. the divisions

I prefer mechanized fast-moving forces, and I like to keep these forces moving together. Therefore, I design my divisions so their speeds are all more or less the same while still possessing great versatility and power.

There are three main division formats I use: the mobile infantry division, the armor division, and the auxiliary division.

for my mobile infantry divisions, the bread and butter is, obviously, motorized or mechanized infantry, preferably mechanized.

mobile infantry composition:

3 motorized/mechanized brigades

1 engineer brigade

1 sp artillery brigade

now, some of you may go "well wait why no armor brigades?" I will explain that later on. This division composition works beautifully for me in pretty much all situations. the mobile inantry give it speed while providing very little softness, and the sp art adds a good punch. the engineer brigade adds river and fort attack, and is the basic unit I use to determine the speed of my divisions.

onto the armor divisions. These I open up to a little bit of variation, but not too much.

armor division composition:

3 armor brigades
1 mech/mot brigade
1 eng brigade

the alternatives I will consider will be substituting an armor brigade for a heavy armor brigade, or any of the listed brigades for an sp art brigade.

now, I find this division composition works wonderfully. as with the inf div, the engineers are the base for the overall div's speed, which is why I prefer 3 arm brigades as opposed to any heavy armor brigades, because it takes much more upgrading to get h arm brigades moving 8 kph. the mech/mot inf provide the combined arms bonus when used with the engineer, and if you're up to it swapping any brigade for an sp art brigade I find works as well.

the auxilliary division is the exception to my same speed rule. This is because I do not use these divisions for front-line combat. I use them more to provide some added protection to my other divisions, or more importantly, guarding port provinces on my flanks and rear.

auxilliary division composition:

1 AA brg
1 TD brg
1 mech/mot brg
1 sp art brg
1 eng brg

as you can see, the variation in brigades makes it unsuitable for leading charges, as it can at most move only 4 kph. however, as I said, it is good for guarding port provinces, or providing air cover and an added punch to my other divisions if they needed. It is a support and rear guard division. using it out of it's role is disastrous.

II. corps

I debate back and forth between distinct corps (eg all mobile inf divisions in one corps, all armor divisions in another, all aux. divisions and the third). However, I find some of each division in a corps works the best, allowing it to possess all the elements needed for a fight instead of inter corps units.

so, we'll say for each corps:

2 mobile inf divisions
2 armor divisions
1 aux. division

and 5 corps per army.

III. combat

now, here I explain my thinking about a few things. As I said earlier, some of you would probably think it foolish to not have armor brgs in my inf divisions. well, I disagree, mainly because I never deploy one division to engage my enemies in combat. all my divisions work in pairs. a mobile infantry division and an armored division fight from the same province, thus providing infantry, artillery, engineers, and armor in a single fight. this works well in overwhelming targets with both soft and hard attack, and is the best counter to at/td equipped forces, or fortified troops. the auxiliary divisions reinforce/attack with these troops where they're needed, and provide effective protection against the air.

The most important thing I find is that my two offensive divisions move TOGETHER. While very powerful on their own, they fight best when they're together, compensating for each other's weaknesses. This is why I try to keep both offensive divisions moving at 8 kph, and why heavy armor is usually excluded from my forces until I've sufficiently upgraded them to move that fast.

as I said from the start, this force setting can be rather supply heavy. I do however feel that it's effective combat abilities compensate for this.

obviously these wouldn't be your ONLY troops. I have a different set up for defensive armies.

IV. defending armies

these units are meant to hold fortified positions along borders. as such, I'm not concerned about engineers or speed, or even armor. I have 2 particular border divisions I use, with some variations. Both focus on infantry (or variations of infantry, such as marines or moutaineers) as their core:

first border division variation:

3 inf brgs (or marine for shorelines, or mountaineers for mountainous terrain)
1 at brg
1 art brg

this provides defence against tanks, some good stopping power, and anti-infantry capabilities. in a fortified province this division can repel pretty much anything, especially when reinforced by the second border variation.

second border division variation:

2 inf brgs (or marine for shorelines, or mountaineers for mountainous terrain)
1 aa brg
1 at brg (or engineer brg if you feel like it)
1 art brg

this provides the missing added air protection, will further enhancing the all around defensive capabilities.

the benefits of these two division types are that they cost NO fuel, are fast and relatively cheap to build, and can hold the line against pretty much anything, especially if in fortified positions. the majority of your forces will be these types of units, which means you only need a few of the offensive forces to attack.

a good example is germany vs france. if you have these border units on every fortified province along the german-french border, attacks by your opponent will be risky and costly. Meanwhile, all you'll need is a force as small as 1 full offensive army to blow through your opponent and rapidly capture important provinces.

well, that's how I like to build my armies. feel free to share your ideas and strategies!

 

[blue emu]

For Motorized Divisions, I usually prefer MOTx2/TDx2, which gives me the Combined Arms bonus, usually +40% or so. This more than makes up for the unit's lower stats. Other benefits are low Manpower requirements (about 8 Manpower per Division instead of 10 or so), allowing me to build about 25% more of them at the same Manpower cost and also making them cheaper to reinforce back up to full strength after a fight; and the combat width of two instead of three, which allows me to attack with six of them across a frontage of ten instead of being limited to using four of them at a time.

 

[Oof]

In the end it all depends on the country you are playing, available leadership and available man power. I.e. Japan has no need for Arm Corps and cant spare the leadership to research the tech required. England may have the need for bgd like eng or art but has little man power and not enough leadership to keep all those techs up to date.

Something I never research are heavy tanks. They are a high leadership and IC investment and only slow down arm div(8 and 4(?) miles). I rather improve my excisting medium panzer units

I like to keep my armies standard (like most players I guess):
- Arm corps: 2 mot (3 mot reg) + 2 arm (2 arm reg + 1 mot/mech reg)
- Inf corps: 4 (3 reg) inf div
- Mnt corps: 4 (3 reg) mnt div
- Airborne: contructed usually three div (3 reg).
- Air transport: the same amount as airborne div, used for air supply and airborne assault.
- Mar Corps(?): 4 (3 reg) mar div. the corps hq is depended on deployment!
- Gar: 3 reg for home country and strategic spots like Cherbourg when playing Germany.
- Gar: 2 reg for non essential locatiosn like Cyprus or India.
As i said attached bgs are depended on available man power and leadership.

Armies: I have no standard army. An amry hq will get the amount and sort of corps i think it needs. So flexibility is my choice.

 

[Fewrfreyut]

yes you're right it does depend on the nation. I know the Soviets and Americans and Germans (Italians perhaps?) could use the army compositions I've outlined. Pretty much every other nation I'll either use those basic forces (IE 3 mot for inf div or 2 arm 1 mot for arm div), or I'll build those defensive force compositions I outlined above and use em as offensive forces.

one thing I dont like using are garrisons. I like having some decent speed in my units (4kph), so the slow garrison brigades I rarely use except perhaps on single province islands, where a bit of movement speed is unnecessary.

I hardly ever use strategic redeployment, although I think it would be a good idea to use it to rapidly divert troops (say for example after defeating poland as germany and using strat redep to get those forces to the western front)

 

[unmerged(88697)]

Few writes: <<II. corps . . . I debate back and forth between distinct corps (eg all mobile inf divisions in one corps, all armor divisions in another, all aux. divisions and the third). However, I find some of each division in a corps works the best, allowing it to possess all the elements needed for a fight instead of inter corps units. so, we'll say for each corps:

2 mobile inf divisions
2 armor divisions
1 aux. division

and 5 corps per army.>>


Looks like you're just beginning to get on track. I began doing things using a spreadsheet, working all the angles, determining total manpower, supply, and fuel. Turns out, there's much more to it than what meets the eye (and that's before one gets into MODs).

Everyone must discover this for themselves eventually, but here are some hints.

Army design: Build armys, and fight with armys. If your armys move as a unit, and fight as a unit, then you will always win over the opponent who does not (SP or MP). Corps are merely sub-units of the army, so feel free to mix and match depending on circumstances; for instance, a mix of light and medium armored corps, or a mix of regular infantry and marine corps, or a mix of cavalry and mountain corps. Think about how your army will be advancing, the terrain, infrastructure, etc., then select corps that will complement one another.

Corps design: There are two rules to success; stack and width. Consider this carefully, stack of 4 and width of 10. Second, remember that pre-war (before spearhead doctrine) armored units have a width of 2. Corps can also be designed to do more than one thing, but that kind of versatility takes real planning.

Division design: Everyone has their favorite combinations of brigades-battilions (2-2, 3-1, 4-0, etc), and each has various strengths. But, don't be fooled as there is no one-size-fits all. Design your forces top-down, that is army, corps, then divisions, and by the time you come down to this level you'll already know what you want to do.


“I have never, on the field of battle, sent you where I was unwilling to go myself; nor would I advise to go a course which I myself was unwilling to pursue." Nathan Bedford Forrest

 

[=Mike=]

(as a larger nation).
Personally 1Med Armour and 2 Motor/Mech. I may throw in a TD (for facing the SU). It gets a combined arms bonus which is really important imo, and is fast. I occasionally add an engineer to armored divs.
I may have some marine only divisions to cross rivers with if required and take ports via amphib assault.
For inf units I tend to just go with inf and either an addition of art or at, or both if feeling extravagant. Keep all techs up to date, or depending upon nation, doctrines to match the bulk of the force.
I would never put pure mech/mot and pure armour divisions, even with TD etc. Why? Because of combined arms bonus. You miss out on it, and if you really keep a mech/mot and arm divisions in same province, then there's no point in not mixing them into 1 med arm + 2 mech/mot in my personal opinion, and gaining that combined arms bonus

 

[Fewrfreyut]

@Mike:

I'm not sure if you think I don't use mixed units for the comb arms bonus, but I do. Engineers plus 1 mech brg give me the bonus in my armor divisions, and the sp art brg gives it in my inf divisions. if you're just saying it in general, then I agree 100%.

for smaller or geographically dense places like Brazil, I find infantry divisions with 3 inf brgs and 1 art brg work extremely well against my neighbours, since the art gives extra firepower without increasing width, and since they have no armor units at brgs can wait until the 5 brg/div tech is done

 

[blue emu]

I'm not sure if you think I don't use mixed units for the comb arms bonus, but I do. Engineers plus 1 mech brg give me the bonus in my armor divisions, and the sp art brg gives it in my inf divisions.

SP-Art does not give the Combined Arms bonus to 3-Regiment Motorized Infantry Divisions, no... you need to drop below 67% softness to receive that bonus, and MOTx3/SP-ARTx1 is no-where near that limit. Try MOTx2/TDx2 instead.

I seriously doubt that MECx3/SP-Artx1/ENGx1 is hard enough to receive the bonus either.

 

[=Mike=]

@Mike:

I'm not sure if you think I don't use mixed units for the comb arms bonus, but I do. Engineers plus 1 mech brg give me the bonus in my armor divisions, and the sp art brg gives it in my inf divisions. if you're just saying it in general, then I agree 100%.

for smaller or geographically dense places like Brazil, I find infantry divisions with 3 inf brgs and 1 art brg work extremely well against my neighbours, since the art gives extra firepower without increasing width, and since they have no armor units at brgs can wait until the 5 brg/div tech is done

It was in general overall, but also to you too If you're getting a combined arms bonus, then its my error entirely - I thought you wouldn't

 

[Fewrfreyut]

no it turns out you and emu are right. it doesn't give comb arms. odd. but oh well. My apologies gentlemen

in that case I'd sub out 1 mech brg for a light arm brg. or maybe a full arm brg.

 

[GAGA Extrem]

Army compositon is a very interesting question.
I have tinkered with it for many games now, but still I feel that the "perfect" solution is far, far away.

There are some core questions you will have to answer for yourself each time you play:
(1) Do you want to use armor? Or at least fast (MOT/CAV) units?
(2) Will your main combat unit be a pure INF or a mixed brigade?
(3) What is your weakest point? Is it IC? Manpower? The supply network? Enemy air units?
(4) How much leadership can you spare for teching? How many different units can you keep up to date?

Usually different countries will have unique desires for their OOB. As the USA for example you can rely heavily on motorized and mechanized units, while JAP will have to take good care about it's fuel stockpile and the mointains in CHI.


Personally, I divide my units into different groups:
(1) Main combat units - the bulk of my army will be like these.
(2) Support units - these usually have lower overall combat stats, but are specialized in a certain role (like AT, AA, fort assault)
(3) Reserve units - this are usually MOT and MECH units that are supposed to play firebrigade tasks
(4) Armour units - usually containing tanks and used for either breakthrough or fast flanking attemps.
(5) Garrison units - usually lightly armed, used to protect airfields and harbours. For important strongholds, I sometimes use super heavy divisions.

In addition, I organize my army at different levels:
(1) Corps usually receives some light reserves.
(2) Army usually receives specialized support units.
(3) Army groups usually receive my armoured divisions.
(4) Theatre usually receives garrison units and support units.

My regular OOB consists of 3-4 "main" units and 1-2 "support" unit, so for example an INF corps could look like this.
I usually prefer divisions with a frontage of 4, since this allows me to use 3 divisions if I am attacking from a single province and 4 if I am attacking from two provinces.


Some example division setups:

INF/INF/INF/INF -> Pure main combat unit.

INF/INF/INF/ART -> Mixed main combat unit.

INF/ART/ART/ART -> Artillery divisions for bottlenecks and other dense situations.

INF/INF -> Light divisions for remote combat areas.

INF/AT/AT/AT -> Heavy AT support unit. Can be added to army or army groups as reserve to counter enemy tank breakthroughs.

INF/AA/AA/AA -> Heavy AA corps. Can be used as mobile reserves to counter enemy bombers and cover your airfields. Probably good for army group level.

INF/INF/INF/AT -> More AT (duh) oriented infantry, no main combat unit, but could be added to each corps to provide some overall AT protection.

INF/INF/ENG/ENG -> Special assault units for fort, river and city combat. Will usually require two full corps for maximum combat efficiency. Work quite well for frontal assaults on the maginot line as GER.

MAR/MAR/ENG/ENG -> Deluxe version, but usually to costly to build enough of them. Is also good against heavily fortified islands.

MOT/TD -> Light and fast response unit, can be added to a corps or an army.

MOT/MOT/TD -> Regular motorized division. Provides CA once ligh armor level 4 (iirc) is researched and has decent AT capacity.

MOT/MOT/TD/TD -> Heavy motorized division. Is used if I can't reach CA for above division early enough.

MOT/TD/TD/TD -> The same, even higher AT power, but much more costly.

MECH/MECH/MECH/TD -> Heavy CA division. Massive firepower and decent AT.

MECH/MEC/MECH/LARM -> Faster than above division, but less AT power.

LARM/LARM/MECH -> Fast armoured division. Nice for flanking and cheaper than MECH focused divisions.

ARM/ARM/MOT -> Plain armoured CA division. Provides more firepower than LARM, but is slower and requires more IC and supplies.

HARM-HARM-MECH -> Anti-tank armoured division. Very low softness, CA bonus and very high AT attack.

HARM-HARM-HARM-HARM -> Defensive heavy tank division. Receives no CA bonus, but has very low softness (10%) that makes it very effective against units with low hard attack, esp. when on the defensive. (Even more since defensiveness and thoughness are (still?) bugged).

SHARM-SHARM -> Garrison armor units. Garrison armor? Yep. Insane cost and supply demand (not to mention tech effort), but if you can place these on an island or another difficult terrain, the only way for your enemy to take the province is either bombing you into oblivion or cut your supply lines.

PAR/PAR -> Light airborne, good for cutting off the enemy.

PAR/PAR/PAR -> Regular ariborne.

PAR/PAR/PAR/PAR -> Requires airborne warfare (and cargo?) tech, but provides maximum firepower for dropped combat.

GAR/GAR -> Light garrison. Can be used to cover remote airfields and harbours or give autoamted HQs some units it can place behind the front line.

GAR/GAR/GAR/GAR -> Heavy pure garrison units.

GAR/GAR/GAR/AA -> If you expect enemy bombing. Against heavy bombing, you might want to swap another AA in.

MTN/MTN/MTN/MTN -> Regular mountain division. Good for rugged terrain.

MAR/MAR/MAR/MAR -> Regular marine division. Using a pure division reduces amphibious penalty to a minimum.

CAV/CAV -> Fast and cheap reserve unit. Good for partisan hunting behind the frontline, since it can fend them off even without tech investment.


Some notes:
(1) Why no POL brigades? Well, unless it has been changed, supression has no effect on revolt risk, making this brigade entirely useless.
(2) Why not add a single ENG brigade to boost combat power for rivers and difficult terrain? Why no ARM/ARM/ARM/ENG divisions? Because the bonus for ENG brigades is very low in vanilla - and since only a quarter of your division consists of ENG, the bonus game will calculate a mean value for the division as a whole. And since tanks heavy HUGE penalties, a single (or even two) ENG brigades will not make enough difference.


An example army OOB:

Theatre HQ
- GAR/GAR (x10)
- INF/AA/AA/AA (x4)

-- Special Corps (x1)
--- INF/INF/ENG/ENG (x5)

-- Mountain Corps (x1)
--- MTN/MTN/MTN/MTN (x5)

-- Army Group HQ (x4)
--- INF/AT/AT/AT (x2)

---- Panzer Corps HQ (x1)
----- ARM/ARM/MOT (x3)
----- MOT/MOT/TD (x1)

---- Army HQ (x3)
----- MOT/MOT/TD (x1)

----- Corps HQ (x4)
------ INF/INF/INF/ART (x4)
------ MOT/TD (x1)


Now, to finish this wall of text, I have some questions of my own:

(1) Is it worthwhile adding brigades to your HQs? Sure, they should not fight, but I often thought that (at least when I am in manual control) brigaded HQs could replace my special support units. HQ/AA/AA/AA could provide some welcome aircover, while HQ/AT/AT/AT could serve as emergency AT response units. You could even try HQ/TD to replace the regular MOT/TD divisions.
Can anyone comment on the effectiveness of brigaded HQ?

(2) Pure main combat units or not? I am still not sure if it is better to have INF/INF/INF/INF or if I should use INF/INF/INF/ART. Sure, ART has more firepower, but it requires more research (2-4 techs) and more supplies. And ever since support brigades take casulties while in combat, I noticed that my ART brigades usually take huge lose ORG and STR losses. And since the remaining INF will fight on much longer, ART takes more losses while it cannot even shoot at the enemy anymore. I ran a test as SOV with pure INF and mixed INF and found that both setup had almost similar manpower drain when reinforcing, even though ART requires much less MP when it is build...
What is your main combat unit? Pure or mixed?

(3) Has anyone tried "pure" armoured divisions? Like the HARM-HARM-HARM-HARM I mentioned above? Granted, the CA bonus is huge, but against any regular unit, low softness could still be strong enough to forgo the 20-50% CA modifier...

(4) Are AC, SP-ART or R-SP-ART usefull? As for me, AC seems to be a very situational unit. Cheap, yes, but they have their own techs and you still need LARM techs if you want to max them... SP-ART and SP-R-ART are faster and have lower softness, but they require much more IC and supply - and I find MOT to be a much better addition instead of these...

Cheers,
GAGA

 

[Leckan]

The infantry troops when playing Germany are usually split up like this:

33% - 3x Infantry
33% - 2x Infantry 1xAT 1xArt
33% - 3x Infantry 1xEng

And as mobile troops I either use

2xMot 1x/2xArm
or
2xMot 1xTD 1xSPart

I haven't done any deeper research in to it like spreadsheets so I'm not so sure that they are that good though as some of you guys have.

I really do like engineers though, I kinda fell in love with them after they helped me breach the maginot line pretty easily, and I figured they're a great asset when attacking across those rivers in Soviet.

If anyone got any tips that is extremely appreciated, I didn't know for example that you was required to have below 67% softness to get combined arms bonus until I read that here so I still consider myself a newbie on a lot of details in this game.

 

[blue emu]

As I've posted in a number of other threads, I prefer to use units with a combat width of two instead of three (or four), allowing six of them to attack on a one-province front. Typical builds would be INFx2/ARTx2 or MOTx2/TDx2 (which gains the CA bonus). Combined Arms corps of Motorized/TDs are very cheap once your Mobile practical has improved, and since MECH shares this same practical, they will save you a huge amount of time and cost when you eventually get around to building some MECH.

 

[unmerged(207443)]

Wow! All good ideas.
Based on my experience IRL and also this Game, establishing a set formation for a division and sticking to it is the way to go.
These are the division formations I use:
Infantry: 3xInf; 1xArt; 1xAT
Armor: 2xLtArm; 1xMot; 1xSpArt ---> Upgrade as soon as possible to 2xArm; 1xMech; 1xSpArt; 1xEng
Ratios for production planning are 4 Infantry division for every Armored division. Clearly the Corps and Higher composition will change based on the battle needs.
I also have found the following useful:
Artillery Division: 3xArt; 1xAT; 1xADA -> very helpful at the Army level for breakthrough firepower later in the game.
Garrison: 3xGar; 1xArt; 1xMP --> very versatile to guard borders, secure major headquarters and provide occupation forces
Armored Cavalry: 3xAC; 1xLt Arm; 1xSpArt --> Useful in the rear areas to quell rebellion and also screening ahead and to the flanks of a major breakthrough formation.
Airborne and Marines I keep to 3 brigades. This is easiest for insertion and I can add supporting forces as needed after the initial assault.
That's it. Any thing else is TMMP- too many moving parts.
ohh...may be an AT and/or ADA battalion at corps headquarters in the break-out blitz. Keeps your experienced corps commanders from getting whacked.

 

[Leckan]

How's 2xInf; 2xTD?

They give an equally nice "soft" attack as 4 inf but their hard attack is increased by a lot, and they also get combined arms. Any thoughts?

 

[Piktoonis]

When i played Germany i used 2inf+art+at and 2arm+mot/mech+spart, so less research to various fields and i could focus on navy, and once i got superior firepower, just added one more inf brigade to infantry and 1 more spart to tank divisions. The idea was to have infantry as main strike force and tank corps for encirclement and pocket destruction force.

 

[Fewrfreyut]

glad to see we're all pitching in here let's keep it going!

perhaps I'll create a navy compositions thread and an airforce compositions thread so we can get some ideas circulating on those too. I know those two fields are where my combat skills seem to lag a tad.

 

[blue emu]

(1) Is it worthwhile adding brigades to your HQs? Sure, they should not fight, but I often thought that (at least when I am in manual control) brigaded HQs could replace my special support units. HQ/AA/AA/AA could provide some welcome aircover, while HQ/AT/AT/AT could serve as emergency AT response units. You could even try HQ/TD to replace the regular MOT/TD divisions.
Can anyone comment on the effectiveness of brigaded HQ?

(2) Pure main combat units or not? I am still not sure if it is better to have INF/INF/INF/INF or if I should use INF/INF/INF/ART. Sure, ART has more firepower, but it requires more research (2-4 techs) and more supplies. And ever since support brigades take casulties while in combat, I noticed that my ART brigades usually take huge lose ORG and STR losses. And since the remaining INF will fight on much longer, ART takes more losses while it cannot even shoot at the enemy anymore. I ran a test as SOV with pure INF and mixed INF and found that both setup had almost similar manpower drain when reinforcing, even though ART requires much less MP when it is build...
What is your main combat unit? Pure or mixed?

My usual Infantry set-up is a Corps composed of five INFx2/ARTx2, plus a Corps HQ Division composed of HQx1/INFx1/ARTx2. This gives me six Divisional-sized units in a Corps instead of the usual five. All of them have a combat width of two. Co-incidentally, when attacking or defending across a single-province front (frontage = 10), the frontage vs combat-width rules allow you to commit exactly six two-width units simultaneously. So my standard Infantry Corps exactly fills the available frontage... and allows me to use 24 Regiments simultaneously in a single-province attack or defense, instead of the usual 12 (for INFx3 Divisions) or 16 (for INFx3/ARTx1 Divisions).

The ART only requires three more techs (two for equipment and one for doctrine). If you are taking high ART losses, the most likely reason is enemy bombing... ART has a special modifier making it unusually vulnerable to Air attack. Cover them with INTs.

The main drawback of the INFx2/ARTx2 set-up is the terrain modifiers, especially Amphibious Attacks. Don't use this unit for Amphibious operations. There is also a small penalty for River crossings... not sure why: can't Artillery fire across a river?

 

[GAGA Extrem]

As I've posted in a number of other threads, I prefer to use units with a combat width of two instead of three (or four), allowing six of them to attack on a one-province front. Typical builds would be INFx2/ARTx2 or MOTx2/TDx2 (which gains the CA bonus).

[...]So my standard Infantry Corps exactly fills the available frontage... and allows me to use 24 Regiments simultaneously in a single-province attack or defense, instead of the usual 12 (for INFx3 Divisions) or 16 (for INFx3/ARTx1 Divisions).

Oddly enough, in my early days I also used INF/INF/ART/ART as a main combat unit.
However, I soon found out that I rarely had use for the full possible frontage, even as a major power. There were some bottlenecks like the maginot line, the inital attack on BEL and LUX, but apart from these I usually used only 3 to 4 divisions per combat. So I still keep two or four "Schwerpunkt" corps ready for the points where I need them, but otherwise I have gone back to INF/INF/INF/(ART/INF).
But, I have to admit, I only play in SP - and given that you can steamroll the AI with almost any OOB, it is hard to derive the true power of my OOB considerations. Have you played some MP games? I heard there are some very different OOB and strategies against human players out there...

[...]If you are taking high ART losses, the most likely reason is enemy bombing... ART has a special modifier making it unusually vulnerable to Air attack. Cover them with INTs.
The main drawback of the INFx2/ARTx2 set-up is the terrain modifiers, especially Amphibious Attacks. Don't use this unit for Amphibious operations. There is also a small penalty for River crossings... not sure why: can't Artillery fire across a river?[/QUOTE]
No, I don't think it is related to air attack. It usually happens all the time, even if I have complete air superiority.
The effect is rather minor during the early years of the war, for example as GER vs POL aor FRA, maybe 5% STR/ORG per combat. But later, probably as tech levels go up and attack values increase, in general all my support brigades seem to take higher and higher casulties. During early Barbarossa I already encounter some divisions that have INF @ 75% and ART @ 25%, While in late war usually one combat usually is enough to know my ART out of ORG and lower it's STR significantly.
The most extreme example was an allied landing in France when I had to move in my local divisions: After some skirmishes I had to detach my ART because it was in grave danger of annihilation.
In general it feels much like in HoI2 when you had a corps of ARM/ARM/MOT and your motorized division always suffered more damage than your tanks, ultimatly slowing you down after a few battles...

Oh and for the river crossing penalty:
Obviously the air above the river has a higher levle of humidity and the resulting friction with water particles slows down the shells and decreases your range. At least in the HoI3 universe.

 

[unmerged(207443)]

from GAGA: "If you are taking high ART losses, the most likely reason is enemy bombing... ART has a special modifier making it unusually vulnerable to Air attack."

Yes. This is not a gamey thing. Artillery was a historically priority target for tactical air and CAS. This is why I include an ADA Bn with my Artillery divisions.