So I once wanted to create a mod myself. One of the main additions to my mod was revamping the way battles were played. My ideas were the following:
1. Ships have their own garrisons, so you cold use them in invasions.
2. These troops wouldn't count against the pop. cap unless they are garrisonned on a planet after battle.
3. Troops on planets basically become more for defense, and thus reduces the credits you spend on land forces
4. Ships can repair, so lost troops, or garrisonned troops can be regained, or maybe to uprade ships with more lasers, fighters, etc.
5. Ships can use garrisons to raid space stations or other ships. While it leaves your ship vulnerable, you have the chance to take over another ship. I do not know how who wins would be determined, maybe by the amount of forces you deploy and testing in a batle who would win.
Thanks for looking, and what do you think?? Good idea, good idea but it won't work, it's idiotic, what do you think? Feel free to modify this or suggest other additons.