First lets see what is wrong:
Right now planetary invasions in Stellaris are more of placeholder rather then valuable feature.
Player simply builds as many cost efficient armies (assault, clones) and tows a huge swarm of transport after main battle fleet.
Sieges are just sitting in orbit, while the 'defenses' number is reduced to zero, then invasion. Invasion are extremely implausible, because invaders often rely on numbers rather than quality.
How should it be:
Defenders have billions in manpower, but mostly poorly trained recruits, defensive bonuses (even after bombardment), third grade armaments, but almost infinite reinforcement pool.
Attackers are badly outnumbered, they can't rely on reinforcements, but have cutting edge armament elite training and are genetically bred for battle, cyber-enhanced or psionically gifted , also surgical strikes from orbit and air support from carriers, which can use exoatmospheric their fighters for ground support.
So land war is about cutting through defenses, taking critical victory points, rather then killing all the defending armies in battle. Defenders must hold long enough to wear down the attackers, while attackers must advance quickly to take the key points like HQs, before they are out of steam.
Orbital bombardment should be either:
1. Very slow surgical strikes, to soften defenses, rather then reducing to 0.
2. Quick and ruthless bombardment, defenses are reduced mush faster, pops die, improvements are destroyed, planet gets permanent habitability malus.
3. Genocidal. Simpy kill all life on the planet, once shields are down, planet becomes barren and uninhabitable or possibly tomb world.
The latter option should instantly make you look like a very bad guy, it's an equivalent of purging of all the population.
What are changes needed for armies:
1. Cost of transports. Now they are practically free addition to all armies except defensive. They should be much more expensive. Each transport can carry certain amount of troops (new module for that probably?). A ship able to lift 100.000 troups with their tanks, guns, supplies should cost at least like a cruiser.
2. Bigger variance in armies: cheap cannon fodder or strong elite. 10 cheap armies that cost like one elite army, but have strength like 2 elite armies. You typically don't use cheap armies for invasions, because of the cost of transports.
3. Frontage: If there are 1000 armies vs 10 armies, no more than 30 vs 10 fighting at any given time, the rest of defenders stay in reserve, they are unable to throw everything at once and must wait their turn to be butchered.
4. Virtually infinite garrisons.
5. Invasion progress: as battle goes, invaders proceed taking objectives, this is shown as growing invasion progress number, when it is 100% - invasion is successful regardless of number of remaining defenders. If invaders face only "free" garrison armies, they advance quickly. Entrenched defensive armies force them to fight for each step forward, slowing advances and grinding invaders down.
6. Whole new role for carriers. It's hard to take well defended planets without direct air support, carriers are now relatively weak in space combat, giving them a support role for invasions makes sense.
Right now planetary invasions in Stellaris are more of placeholder rather then valuable feature.
Player simply builds as many cost efficient armies (assault, clones) and tows a huge swarm of transport after main battle fleet.
Sieges are just sitting in orbit, while the 'defenses' number is reduced to zero, then invasion. Invasion are extremely implausible, because invaders often rely on numbers rather than quality.
How should it be:
Defenders have billions in manpower, but mostly poorly trained recruits, defensive bonuses (even after bombardment), third grade armaments, but almost infinite reinforcement pool.
Attackers are badly outnumbered, they can't rely on reinforcements, but have cutting edge armament elite training and are genetically bred for battle, cyber-enhanced or psionically gifted , also surgical strikes from orbit and air support from carriers, which can use exoatmospheric their fighters for ground support.
So land war is about cutting through defenses, taking critical victory points, rather then killing all the defending armies in battle. Defenders must hold long enough to wear down the attackers, while attackers must advance quickly to take the key points like HQs, before they are out of steam.
Orbital bombardment should be either:
1. Very slow surgical strikes, to soften defenses, rather then reducing to 0.
2. Quick and ruthless bombardment, defenses are reduced mush faster, pops die, improvements are destroyed, planet gets permanent habitability malus.
3. Genocidal. Simpy kill all life on the planet, once shields are down, planet becomes barren and uninhabitable or possibly tomb world.
The latter option should instantly make you look like a very bad guy, it's an equivalent of purging of all the population.
What are changes needed for armies:
1. Cost of transports. Now they are practically free addition to all armies except defensive. They should be much more expensive. Each transport can carry certain amount of troops (new module for that probably?). A ship able to lift 100.000 troups with their tanks, guns, supplies should cost at least like a cruiser.
2. Bigger variance in armies: cheap cannon fodder or strong elite. 10 cheap armies that cost like one elite army, but have strength like 2 elite armies. You typically don't use cheap armies for invasions, because of the cost of transports.
3. Frontage: If there are 1000 armies vs 10 armies, no more than 30 vs 10 fighting at any given time, the rest of defenders stay in reserve, they are unable to throw everything at once and must wait their turn to be butchered.
4. Virtually infinite garrisons.
5. Invasion progress: as battle goes, invaders proceed taking objectives, this is shown as growing invasion progress number, when it is 100% - invasion is successful regardless of number of remaining defenders. If invaders face only "free" garrison armies, they advance quickly. Entrenched defensive armies force them to fight for each step forward, slowing advances and grinding invaders down.
6. Whole new role for carriers. It's hard to take well defended planets without direct air support, carriers are now relatively weak in space combat, giving them a support role for invasions makes sense.
