I'm sorry, I'm afraid I don't get it.
Why is the battle system so convoluted?
I can only send out a certain number of a certain type of troop...but also only a certain number of troops in general? Even if the enemy is defenseless it can still be a stalemate if I run out of troops? Even if they're only one hit left away from defeat, I lose my gold star because...why?
Plus, resources seem a bit tight, all things considered. Since I obviously don't just have troops for fighting, but for...occupying...I need to balance sending strong troops to kill and weak troops to occupy, whilst keeping track of my population meter, whilst keeping track of my resources to run out of neither, WHILST making sure both are strong enough to kill off an enemy rather than straight up die because the enemy had a bunch of passive upgrades I was unaware about.