The castle of your dreams.

Yes, just make the fairies level 1, and leave the centaurs, but make them level 2 and stronger, because they are too weak (especially their health). In general, I would add an ancient race, like the Archons from Age of Wonders, and call them Atlanteans, for example, to avoid any problems. They have Amazons, Legionnaires, chariots, saints, and even Titans. :smile36:

Added 3 minutes later
Well, move the dwarves to their new ice castle, and the mages to the desert. And I would remove the elementals, because I don't play as them very often; make the creatures neutral or, instead of fairies, add some weak spirits (e.g., sylphs and oceanids).