Iratus, Lord of the Dead except it's a tactical RPG instead of the more simplified combat that it is. Sprite aesthetics and tile based tactical maps.
Minions are cheap and plentiful. You still create minions from harvesting defeated enemies. Later on, conquered territories supply you with other resources to summon more complex/intelligent minions (sacrificial rituals to summon demons, for example). Early minions are dumb: you can give them simple commands that they will attempt to carry out through AI on their own turns (tentative, might not make for good gameplay). More intelligent minions can be commanded/controlled more directly.
A skill tree to focus on certain minion types. You have a cap of how many units you can command in combat, skill trees would allow you to allocate additional units, among other benefits. For example, an undead-focus build would let you throw out many extra zombies but wouldn't increase your generic/intelligent minion pools as quickly.
Limited recruitment of named characters. Ideally none, but that makes story-telling more difficult. Game should have an extensive campaign and story, similar to FFTactics or Disgaea, maybe with a give-and-take strategic map like Emperor: Battle for Dune or Dawn of War DC/Soulstorm (you'd have story-based goals but could go and backconquer adjacent but story-unrelated territories). More territories conquered provides more souls/resources for your skill tree and minion progression.
Might keep the stress system of Iratus but maybe lean more on the RPG side and allow players to grind to pass difficult encounters (game would be easier overall).