The land warfare in Stellaris is going to be annoying long as the transport ships need babysitting. Even with the recent improvements to the transport ship behaviour (most notably that they remember the aggressive setting after each invasion) there is always chance that the transport fleet goes to follow the wrong fleet, jumps to the next system before the warships and gets destroyed etc.
While my earlier example about "just throw more rocks" was glib, I am not outright against a system which would turn planetary invasions to a more compelling mechanic. I don't like idea of heavily restricting number of armies or speed they can be built without also changing how they are moved to the enemy planets as like I said currently the transport fleets require way too much babysitting during any larger war.
Conquered planets turn into productive planets way too quickly. Invading a planet with hostile people is hard, but actually occupying the planet and turning it into a something productive should be far harder. I don't have any realistic ideas for the current game, and the few ideas I have would probably hamstrung the AI very badly.
Personally I am not expecting many, if any, changes to the land warfare until Stellaris 2. The fronts in Victoria 3 seem interesting and I could see a similar system working in Stellaris, too, as the planetary warfare over a single planet should not be a very big focus in Stellaris much like warfare and single armies etc. are not the focus in Victoria 3. Maybe the front could include the entire solar system or even multiple systems so you would have to provide troops, military ships to guard them and make orbital strikes, escorts and transports for the new supplies and reinforcements etc.
At the same time the planets would need some heavy duty protection, too. Without a friendly fleet to defend the planet the attacker could send constant barrage of kinetic weaponry (including asteroids etc) against the planet well outside of range of most weapons though obviously scifi and space magic could solve this. Planets have really bad dodge-%. Unsurprisingly David Weber had a fairly compelling example ("Dahak" series) planetary based weapons what could be used to defend a single planet in that specific universe - they had a long range standoff weapons but they could be launched only in a vacuum if I remember right.
1.
Hence my Suggestion to make Armies into their own Fleets which then will be able to carry out Bombardments and Smaller Scale Battles themselves. Thus not requiring much Babysitting.
At the same time. As you got Set Armies with their own Units that can be Replenished the same as Fleets. You also no longer have to constantly manage small Units and sort them into the actual Armies.
2.
I Agree that Planets should take far longer to become Productive. And Frankly should Require Pacification and Occupation for Years.
Currently. This mechanics was mostly dropped because it was easy to just Build some Cheap Armies and put them everywhere to increase Stability.
But this Problem would actually be solved by my Suggestion Automaticly.
After all. If you only got a Limited Number of Armies. You can give each Army a Suppression Value similar to the Anti Piracy Value on Space Fleets.
And then can use these Armies to Suppress and Occupy Conquered Planets. Or to Pacify your own Planets with Stability Problems.
But always only for a few Planets as you only got a few Armies.
You could even make that Effect be similar to Piracy and have a somewhat lasting effect so that you can have your Armies Patrol a few Systems.
3.
Problem with this once more is that David Weber assumes Inequal Technology or Technology were Planets are unable to Sense and or Affect far into their System.
But given Stellaris Lore so far. Planets can actually Locate and Track Enemy Fleets even several Systems Accross.
Especially Kinetic Attacks are going to be fairly Irrelevant as well. Because on a Range where the Fleet is outside the Planets Attack Range. The Planet also would have alot of time to Intercept and Destroy any Incoming Attacks.
Thats the thing. In Stellaris. FTL Travel only works outside the Gravity Well of the Star.
Inside the System everyone has to rely on the Sublight Engines.
The Planet is generally at a Disadvantage because his own Gravity Well will Slow down Projectiles Fired by it and Speed up Projectiles Incoming.
But this effect is Neglectable for the Speeds and Ranges which Kinetic Weapons are Fired in this Game.
But more Importand is. This Advantage only counts for Large Objects.
In Fact. For smaller Objects the Planet actually has a Large Advantage. Because the Attacking Fleet has to use fairly Big Projectiles to avoid their Attacks just being Destroyed by the Planets Atmosphere and thus not causing any Damage. This becomes even more true when the Planet has Shields or Fortifications that wont be Impressed with a nearly Molten Projectile thats just gonna Splash on its Heat Shields be they Physical or Energy in Nature.
The Reason is that the Atmosphere will destroy Objects without Sufficient Mass even if they Hit it with almost Light Speed. (This is why smaller pieces of Rock hitting Earth at insane Speeds wont cause Large Craters due to their Immense Energy (their mass x their speed) which would cause Giant Crater if hitting a Planet without Atmosphere. Are generally not doing much beyond producing a bit of a light show for us at Earth)
But the Fleet has no Atmosphere. So the Planet can actually Lunch Super Small Projectiles that are very difficult to detect and Intercept at Insane Speeds which upon Impacting the Fleet would cause Tremendous Damage.
But thats a different story really.
Almost any configuration can be explained by a proper Scify Scenario really.
Thing is.
In Stellaris. Planets right now are effectivley totally underrated given their actual Power.
Planets are the Giant Backbone of the Production an Empire has. Yet in Wars they are a total Backseat which have almost no Defensive Power and almost no direct Strategic Value.
Because the Ressource Stockpiles are generally offmap or in Space Stations. And all actual War effort takes place in Space.
Planets should be way more Importand and way harder fought for.
Frankly. A Planet is so Importand that a War between two Empires in the Early Game. Should often all be about Conquering a Single Planet from the Enemy.
Stellaris has recently become way too small.
With the Galaxy being more of a backyard rather than the massive Place its supposed to be.
Yes, remove the whole ground combat mini game (if you can even call it that) and replace it with orbital bombardment. Simple, easy, AI can handle it, done. Endless Space had a really amazing way of handling it. You could outfit your ships with extra crew/soldier components which would make the bombardment/invasion happen faster. It was all automatic and a really well thought out system. Ground combat in Stellaris is annoying micro and the AI has enough problems using it.
If you want to Play Space Wargames go Play Sins of Solar Empire or Homeworld or something.
This is Stellaris. Its an 4X Game not an RTS Space Wargame.
As for the AI. I already addressed that. This is due to the Bad Implementation. Its got nothing to do with Ground Combat itself.
If we remove any Mechanic the AI has problems with instead of Improving them. You wont have much of a Game left.
