They are quite balanced I think. Everything is good: infantry, cavalry, magic, Single Entity, Artillery.
Magic is a stronger point. You have a nice lore book, plus many units can cast magic spells for free. So you can cast a lot of spells.

Then I think if you get Jaffar, The legendary hero, all the upgrades, you can get some very elite and cheap infantry in the Palace Guards.

You have many choices for cavalry, some ROR are very very strong, probably in the top cavalry in game.

You can probably DoomStack Djins, and Elephants, but I don't know, it's not my style of playing.