to be honest with you i think this style of game is more fun as the monsters
id love to see two things be changed 3 if you count the gamemode swap but i think its pretty normal
1.futa enemys :) i love females breeding females
2.swap to a form of tower siege where groups of 4 girls get spawned on the map think portal or heli then their goals are to maybe release 10 monster girls the lord [id say demonic but whatever you choose] uses to spawn unholy entitys think cahtulu [bad spelling aka tentical god] you start with 10 unholy ladys these girls would give you some form of powers so a female cahtulu would grant to tenticle minions that can ambush enemys like zerglings but a demonic goddess like lilith might grant to 2 units a sucubus which temps the girls and a incubus that acts as a super heavy carrier unit
3.swap the player to the defender
and abit of info well idk if this would be easy you could make a whole roster of units some could be engineers medics and other things
you could also do this as a two way game you first play the monsters in their kingdom then after you win you start in new game plus as a warrior princess or a goddess and play as the girls breeding the guys instead
like a flipflop of the demonic side