Mechanised infantry, worth composition?

[JakiroZerg]

cost needs to be a huge factor, as mech are so expensive and slow to build that you can never get high numbers of them.

 

[Secret Master]

cost needs to be a huge factor, as mech are so expensive and slow to build that you can never get high numbers of them.

They didn't replace MOT completely during the war, either.

Fielding huge numbers of them should require a massive investment, given their stats.

 

[Pro_Consul]

They didn't replace MOT completely during the war, either.

Fielding huge numbers of them should require a massive investment, given their stats.

Quite so. Even the most profligate nation when it came to equipment expenditures for mechanization, USA of course, relied far more on trucks than halftracks. They used a buttload of halftracks, no doubt, but they employed far more trucks in combat units. In game terms it means they relied far more on motorized than mechanized units.

 

[ltccone]

To me, it boils down to what are you willing to give up to get mech. Tanks? planes? ships? IMO mech is just not worth it.

 

[Comrade110]

They already do cost less than MARM and more than MOT. We covered this several posts back in this thread.

Adding med 41 gives +650 cost to tempalte, adding 1st mech gives 640-650, so they cost the same, higher tier mechas are MORE expensive.

 

[Otto of england]

So lets think what use is a mechanized unit; what roll should it be employed in? Its obvious immediately from the cost, that it does not replace motorized, it is far too expansive and trying to do so is essentially impossible production wise. That leaves the use of specialist divisions, for example the often sited breakthrough support. However, we have to see if it is actually cost effective at that roll. For, a defensive unit should be as cheap as physically possible, as it does not win you wars. The less resources you spend on defence the more you can spend on offence, so lets compare two contrasting division builds for this purpose.

Now these two division builds have to stand up to the most egregious armour division the enemy might use, and one of the most offensively powerful division is a 15/5 armour division (I'm using this as it was sited here). Therefore, we must compose our motorized and mechanized divisions to try and defeat this divisions in both piercing and pure attacks, or at least last long enough that it counter encircle.

So Im comparing these divisions:

Spoiler

This last one cost 9456-9630 IC. I messed up taking the screenshot.

Note: none of these are super optimized, only mostly optimized.
Note2: 1940 tech, except 1943 TD/medium tank. The panzer division has mobile warfare doctrine, the other two superior firepower. Both sides use heavy tank designer.

Analysis:

Spoiler

Key terms:
Base Adjusted Attacks (BAA): the Hard Attack+Soft Attack adjusted to hardness and armour advantage of the enemy.
Real Attacks (RA): BAA adjusted for defence value

Important values:
LAND_COMBAT_ORG_DICE_SIZE = 4, -- nr of damage dice
LAND_COMBAT_STR_DICE_SIZE = 2, -- nr of damage dice
LAND_COMBAT_STR_DAMAGE_MODIFIER = 0.05, -- global damage modifier... but some equipment is returned at end of battles see : EQUIPMENT_COMBAT_LOSS_FACTOR
LAND_COMBAT_ORG_DAMAGE_MODIFIER = 0.05, -- global damage modifier

Im assuming the dice size mean a d4 and d2 not rolling 4 dice of unknown size. Therefore I'm using 2.5 and 1.5 as average values.

For the Panzer divisions we have a BAA of 524.026 vs the motorized version and 511.128 vs the mechanized division.
The motorized division has a BAA of 347.468
The mechanized division conversely has a BAA of 455.37 vs the panzer division.

Panzer vs Motorized
The Panzer divisions has an RA of 53.8804 and the Motorized has an RA of 34.7468

This means that the motorized division does 4.34 org damage per hour and 2.61 strength damage per hour. Or in 10 hours it will break the Panzer division and deal 26.1 strength damage.

The Panzer divisions does 6.74 org damage per hour and 4.04 strength damage per hour. Or in 6 hours it will break the Motorized division and deal 24.24 strength damage.

Therefore the Motorized division does 26.04 org damage and 15.66 strength damage.

Panzer vs Mechanized comparison:
The Panzer division has an RA of 51.1128 and the Mechanized has an RA of 45.537.

This means that the mechanized does 5.69 org damage per hour and 3.42 strength damage per hour. Or in 8 hours it will break the Panzer division and deal 27.36 strength damage.

The Panzer division in turn does 6.39 org damage per hour and 3.83 strength damage per hour. Or in 5 hours it will break the mechanized division and do 19.15 strength damage.
Therefore the mechanized inflicts 28.45 org damage and 17.1 strength damage in the same period.

Combat performance between Mechanized and Motorized:
Taking average cost values. (All values rounded to nearest hundredth)
Motorized:
Cost: 5260
Cost per strength damage: 335.89
Cost per org damage: 202
Equipment Lost: 8.57%
Value of lost equipment: 8.57% * (1110*0.6+550*2.5+24*4+24*5+216*14) = 452.58
Manpower lost: 1594
Enemy Equipment Lost: 9.84%
Value of equipment destroyed: 1152.36
Manpower Killed: 1437
Equipment destroy/equipment lost ratio: 2.55
Manpower killed/manpower lost ratio: 0.90

Mechanized:
Cost: 9543
Cost per strength damage: 558.07
Cost per org damage: 335.43
Equipment Lost: 7.67%
Value of lost equipment: 7.67% * (24*5+24*5+810*0.6+400*12+288*14) = 731.26
Manpower lost: 1266
Enemy Equipment Lost: 10.7%
Value of equipment destroyed: 1253.08
Manpower Killed: 1562
Equipment destroyed/equipment lost ratio: 1.71
Manpower killed/manpower lost ratio: 1.23

tl:dr
When fighting the exact same tank division 15/5 the Motorized division destroys 2.55 IC of enemy equipment for every IC of equipment it losses, whereas the Mechanized division destroys 1.71 IC of enemy equipment for every IC of equipment it losses. However, the Motorized division has a manpower loss ratio of 0.90 compared to the Mechanized's 1.23. We can see then that the Motorized division is 149% more cost efficient and the Mechanized division is 137% more manpower efficient. So if manpower is your limiting factor, then mechanized is worth it, otherwise it's useless.

Other useful stats:
Mechanized vs Motorized cost ratio: 1.81
Mechanized vs Motorized IC loss ratio: 1.62
Mechanized vs Motorized damage caused ratio: 1.09
Mechanized vs Motorized IC per org damage ratio: 1.66
Mechanized vs Motorized IC per strength damage ratio: 1.66

Interesting note Cost ratio/damage caused ratio gives the exact same IC to Org and IC to damage ratios as computing the numbers otherwise. Even though damaged cause is in IC value not org.

 

[Comrade110]

Good analysis otto, mechas are too overpriced in vanilla for no rational reason whatsoever. I dont have exact numbers but Im pretty sure some halftrack armoured vehicle is not as expensive as medium tank Panzer 4.

 

[ocelot64]

Why not a heavy tank -AT added to an infantry division for front line AT duties?

you wouldn't be suggesting to spend 5x the research time on the AT line? ? I rarely have the research time to bother with walking AT, so am not sure about the stat differential between a heavy TAT and an AT gun.

Any tank division deployed by the AI in Single Player can be countered by the piercing value of a traditional support anti-tank company. I think it's a waste of resources and training time using heavy or super heavy tank destoyers attached to infantry divisions. An all infantry division is fully trained in 90 days, an infantry division with most support companies and/or artillery is fully trained in 120 days. Attach a tank destroyer regiment and it goes up to 180 days.

 

[Secret Master]

Any tank division deployed by the AI in Single Player can be countered by the piercing value of a traditional support anti-tank company. I think it's a waste of resources and training time using heavy or super heavy tank destoyers attached to infantry divisions. An all infantry division is fully trained in 90 days, an infantry division with most support companies and/or artillery is fully trained in 120 days. Attach a tank destroyer regiment and it goes up to 180 days.

But in SP, most people are attaching the TDs to get an armor value just high enough to render 90% of AI divisions incapable of piercing. So, your entire army ends up immunized against enemy divisions.

 

[ocelot64]

But in SP, most people are attaching the TDs to get an armor value just high enough to render 90% of AI divisions incapable of piercing. So, your entire army ends up immunized against enemy divisions.

Ah. Well, I didn't think of this aspect.

 

[ltccone]

But in SP, most people are attaching the TDs to get an armor value just high enough to render 90% of AI divisions incapable of piercing. So, your entire army ends up immunized against enemy divisions.

Adding a TD battalion to all of your infantry divisions is a lot of TDs unless you have a small army. As Germany I have about 120 infantry divisions. I could never build enough TDs unless I make major sacrifices somewhere else.

 

[Pro_Consul]

Adding med 41 gives +650 cost to tempalte, adding 1st mech gives 640-650, so they cost the same, higher tier mechas are MORE expensive.

And have you taken even a tiny peek at their relative resource costs? As for more expensive production cost, you are incorrect. The production cost for a singe production unit of MEC is exactly the same as the production cost for a single medium tank of one year later model. All of this having already been covered....

 

[Secret Master]

Adding a TD battalion to all of your infantry divisions is a lot of TDs unless you have a small army. As Germany I have about 120 infantry divisions. I could never build enough TDs unless I make major sacrifices somewhere else.

I don't disagree.

But then again, you won't need a lot of other stuff to smash the AI when their divisions are basically shooting nerf balls at your most basic formations.

You just bulldoze the Soviets to the Urals. It's not a very fun way to win the war.

 

[ltccone]

I don't disagree.

But then again, you won't need a lot of other stuff to smash the AI when their divisions are basically shooting nerf balls at your most basic formations.

You just bulldoze the Soviets to the Urals. It's not a very fun way to win the war.

No, it isn't. I prefer the 'old fashioned approach.'

 

[MadDjinn]

Adding a TD battalion to all of your infantry divisions is a lot of TDs unless you have a small army. As Germany I have about 120 infantry divisions. I could never build enough TDs unless I make major sacrifices somewhere else.

Ah. Well, I didn't think of this aspect.

I wouldn't go full HTAT on all divisions, but I do end up adding maybe 4-6 such divisions per 24 division army for front line quick stop of enemy armour and to push without the needed armour on my side.

 

[Alex_brunius]

tl:dr
When fighting the exact same tank division 15/5 the Motorized division destroys 2.55 IC of enemy equipment for every IC of equipment it losses, whereas the Mechanized division destroys 1.71 IC of enemy equipment for every IC of equipment it losses. However, the Motorized division has a manpower loss ratio of 0.90 compared to the Mechanized's 1.23. We can see then that the Motorized division is 149% more cost efficient and the Mechanized division is 137% more manpower efficient. So if manpower is your limiting factor, then mechanized is worth it, otherwise it's useless.

Other useful stats:
Mechanized vs Motorized cost ratio: 1.81
Mechanized vs Motorized IC loss ratio: 1.62
Mechanized vs Motorized damage caused ratio: 1.09
Mechanized vs Motorized IC per org damage ratio: 1.66
Mechanized vs Motorized IC per strength damage ratio: 1.66

Interesting note Cost ratio/damage caused ratio gives the exact same IC to Org and IC to damage ratios as computing the numbers otherwise. Even though damaged cause is in IC value not org.

There are some other effects that I think your not taking into account here when you pit tank divisions vs tank divisions and use attack (breakthrough) as well as 1:1 division situations.

When fighting on the defense against enemy infantry+artillery (almost no HA), and outnumbered, which is a quite common situation for tank divisions when the enemy tries to break out from encirclement, MEC will get much better numbers.

The higher hardness impact will reduce SA damage taken by a significant amount, but the most important effect is their higher defense which reduce more of the large numbers of incoming soft attacks to 25% as much damage. In some situations the higher armor could also allow the MEC division to overcome the lower infantry AT, where MOT would not, which further improves their impact.


To properly test if MEC is better then MOT for tank divisions you also need to test them out when defending outnumbered against the enemy counterattacks, because that's when MOT/MEC are useful, when their defense values is put to good use. On the attack tanks are the stars (breakthrough), which will make the big difference.

 

[Otto of england]

There are some other effects that I think your not taking into account here when you pit tank divisions vs tank divisions and use attack (breakthrough).

When fighting on the defense against enemy infantry+artillery (almost no HA), and outnumbered, which is a quite common situation for tank divisions when the enemy tries to break out from encirclement, MEC will get much better numbers.

I don't have time right now to number crunch that scenario in particular (I will later), but my gut feeling is the ability for a standard infantry division to damage either of these motorized/mechanized divisions is probably pretty slim. Additionally, you can just about field 2 motorized per mechanized which means you are out numbered much more in frequently. Considering that infantry have almost no breakthrough if you can match them 1:1 on the frontline it should have a similar outcome. Though I will crunch the 1:1 scenario later.

The higher hardness impact will reduce SA damage taken by a significant amount, but the most important effect is their higher defense which reduce some of the large numbers of incoming soft attacks to 25% as much damage. In some situations the higher armor could also allow the MEC division to overcome the lower infantry AT, where MOT would not, which further improves their impact.

I would be surprised if someone bothered to deploy AT in their infantry if they cannot pierce 65 armour. 65 is the low end for a real armour division and if you cannot get to with in a few points of that there is no point in buying AT.

While your correct that the mech should take less damage, the posted division (which is a good example of mech-defence division) has a good chunk less HP and is far more expensive to 1% damage ~= 2% damage on the motorized-defence division. There are very few scenarios where the hardness/defence can make up for that. You would need a division with well over 1100 unmodified attacks to really see the difference. Anythingless then 1000 unmodified attacks means the motorized should always preform better. (The armour division tested has 1054 unmodified attacks)

To properly test if MEC is better then MOT for tank divisions you also need to test them out when defending against the enemy counterattacks, because that's when MOT/MEC are useful, when their defense values is put to good use. On the attack tanks are the stars (breakthrough), which will make the big difference.

Well my test was mechanized or motorized for an anti armour division (note those are all tank destroyers not tanks in the divisions, except the 15/5 division). Since that was the sited use for mechanized in this thread, to defend your breakthrough against counter attack which is only really possible for enemy armour, and the tested divisions are designed to chew through heavily armoured divisions very cost efficiently (as seen by the 1.71 and 2.52 damage/loss ratios).

 

[Alex_brunius]

I don't have time right now to number crunch that scenario in particular (I will later), but my gut feeling is the ability for a standard infantry division to damage either of these motorized/mechanized divisions is probably pretty slim. Additionally, you can just about field 2 motorized per mechanized which means you are out numbered much more in frequently. Considering that infantry have almost no breakthrough if you can match them 1:1 on the frontline it should have a similar outcome. Though I will crunch the 1:1 scenario later.

Well the x4 damage advantage when surpassing defense values quickly does become significant in situations when badly outnumbered though.

If we for example look at either Infantry+ Artillery and use 120-160 width worth of these (2-3 direction attack) overmanning a single 40 width tank/mec/mot division (when you stretch your enciclement to the limits) it should take significant damage.

Or if we use Tanks with SPGs instead which has lower HA values but higher SA so that the hardness added by MEC plays a bigger role.



I do agree with the basic conclusion here that Mechanized focused divisions are most of the time not worth their cost though.

 

[Pro_Consul]

I would be surprised if someone bothered to deploy AT in their infantry if they cannot pierce 65 armour. 65 is the low end for a real armour division and if you cannot get to with in a few points of that there is no point in buying AT.

I disagree on this point. If you are facing an enemy that has fielded a lot of armor, then adding AT to your INF divs is still a good idea even when it cannot, on paper, pierce the enemy armor. The thing is this: armor rating is dependent on the number of tanks present. As the enemy's armor units take losses due to combat and attrition, the number of tanks in each division will fall, dragging down the armor rating with it. Having AT in your infantry formations speeds this process, since the AT guns will still kill some tanks even when their piercing is too low to shed the armor/piercing malus....yet. But as you reduce the enemy's number of tanks, eventually their armor rating will fall to below your infantry divs piercing. And then the enemy had better withdraw those armor divs until they get replacement tanks, or expect to see them get thrashed by "mere" infantry.

 

[Secret Master]

The thing is this: armor rating is dependent on the number of tanks present.

Yep. This is the real bugbear of lengthy campaigns in HOI4.

If you are playing lightning fast games that finish in one or two sessions, misclicks and failing at prioritizing your attention will result in quick losses without the need to worry about replacing lots of tanks over 24 months. You also don't see the effects of less than 100% equipment as often, because you aren't paying attention to the details. That's not a critique, but an observation about how tiny details are missed in some contexts. (In SP, you don't see this happen, because you don't take many losses, and the AI takes so many so quickly, that it becomes something you don't care about.)

In slower games, it becomes a real issue. You can outright notice it more often when it happens: division A is not pierced by division B, until a week into an offensive, then suddenly it is. Unless the enemy magically teleported the next tier of AT guns (does happen) to the infantry, it's probably due to loss of tanks. So, a piercing rating of 40-50 sounds like crap, but after two weeks of fighting in an area with bad infrastructure (or the infrastructure is torn up from the fighting), and after 40 Soviet divisions have been forced to retreat, Soviet division #41 starts to pierce Rommel's panzers. It's not because the Soviets got better at piercing; it's because your panzer divisions have taken enough losses to matter. Even 100 tanks lost to attrition (in a group of 24 divisions) on top of combat losses can hurt enough to make a difference.

I'm not saying you shouldn't strive for better piercing, but being aware of the limits of tank endurance is important.

Relating to MECH:

You also really need to decide on a mission for your divisions before you decide whether MECH needs to be included. If you want to counter enemy armor with your armored divisions, and you know the enemy is using SPART, MECH's reduction in hardness might pay for itself. If you are planning to conduct offensives in terrain where MECH does better than MOT, MECH might be a good idea.

But then again, maybe you inherited a pile of trucks from capitulations and surrenders, but you don't have the oil to produce MECH. Then you just stick some MOT in your divisions and churn out panzers, hoping to win the war before your truck shortage makes a difference. It's really contextual.