RTF is a global modification that replaces all towns in the game.

Then you could call it "Kings of Kings"). In general, you could make it like this: regular, unit-veteran, unit-king.

Well, veteran and king are not equivalent ranks.

Added 48 minutes later
Okay, I've decided who will complement the faction.

The flies won't go anywhere; they'll occupy Tier 3. Flies hatching from the corpses of enemies using Naadir's special ability is cool.
Rotting warriors will move to Tier 2. A specialist in warriors is cool; it will be a necromancer-knight.
I dressed Alaric in the Lich armor from Dark Messiah; that will be Tier 4.
And I can take armor for undead horses from Warcraft, so Tier 6 will have vampire knights, but not handsome ones, but Nosferatu, although maybe the red grade will be prettier.

I want to reduce the size of the fly so that it is unicellular; I'm currently trying to move its parts to Hannik's feathered serpents.