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

Therefore, I still suggest making angels something like a deity for the Necromancer faction, but not using them as heroes/units.

I will say again that this idea is from fktifzobr@mail.ru, not mine, and regarding where the angels will be, you should ask him. As for the dragon riders: In my opinion, this is not a heroic entity at all, although we need to see how it will turn out. After all, the unit must stylistically fit the faction. If we make some kind of ghostly dragons with riders, then why not, but we still need to see how it will turn out.