But that's not all.
Depending on your command rating, or present Generals, you have Strategy Stars which allow you to pick special options called "stratagems" such as Blitzkrieg, Trap, Reversal, Cutoff, Counterattack, etc. Some cost more "strategy stars" than others. You may choose when to employ these stratagems and it takes time for Strategy Stars to get "recharged". You might also pick specific targets for bombardment or certain stratagems.
Obviously military installation hexes would impart huge bonuses to defenders, lesser bonuses to adjacent hexes, provide airbase range, be resistant to bombardment, etc.
Based on your objective and distribution of hexes, you could occupy only population centers, with military bases holding out, besieged and encircled, or you could invade military installations first to be able to utilize them for airbase radius bonuses and turn their anti-orbital firepower and potential shield capabilities against enemy fleet in orbit. It is to be understood that a ship battle is taking place upstairs during all this.
Once you occupy Admin center hex, it's over. You win. Unless it's a nemesis war or enemy population has Defiance trait or something (then you have to fight until eradication).
Add to this the fact that planet hexes are generated according to planet type. Different techs/doctrines would provide bonuses for different terrain types. Oceanic planets will have some hexes as oceans, limiting the landmass for maneuvers. Aquatic species will have subaquatic population centers where only specially equipped armies can go. Etc, etc.
Oh and finally if you are an emperor in your custom mech, you and your elite "bodyguard army" are a unit on the hex map. And you can control that one, and ONLY that one, directly, per-hex. Everything that happens to that unit also imparts a roll against you. Set stance to reckless mellee combat for fast reputation... etc.
So how does it sound, /tg/?