Future expansions.

Um, Minotaurs? Why? Aren't they a separate, original race?

Minotaurs were bred by Warlocks in Krigspire under the leadership of Agar. Some of them created their own culture in other lands (in the labyrinths of Nighon, the Lair of Baltazar) and served in the armies of the Warlocks.

Again, not all of them were bred, and this is mentioned in Heroes of Might and Magic IV. Ifrits were independent and simply joined a powerful "ally."

I didn't say that all of them were bred. There were allies, such as Ifrits and domesticated creatures (Gog, Hellhounds).