[Cyrien]

IF we had a special damage type that canceled the 'damage to kill one population' ratio we could have normal weapons able to destroy planet defenses but NOT population at any reasonable rate, and planetary weapons able to use this special damage type and destroy population/facilities without being cranked up to huge damage levels that can paste planet defenses.

You can almost do something like this with some creative modding. Can increase the damage resistance capacity of weapon platforms to higher levels so they can resist damage better. They always get targeted first so before reaching the planet have to blow through them. In addition increase the amount of damage needed to destroy population. Use the only damages population for weapons to kill the actual population and give them the corresponding damage levels to effectively do so. Use all or a combination of these and you can get some very interesting scenarios for planetary combat and invasion. Only thing that is hard is making facilities harder to kill. Only way you can really do this is adding shielding to them which affects the planet as a whole and protects all the units etc as well.

I have some of my own custom mini mods that alter things like this with the good planet invasion AI files to make ground combat much more important for taking over a planet without removing the need for planetary bombardment (to kill the WPs) or the option for glassing the planet (if you invest in bomber ships and the tech).

Would be nice if there were easier ways to do it of course.