Neither Xeron, nor Sandro, nor Catherine are leaders of races.

That's not what I meant. Sorry, I haven't read any lore about Might and Magic and I don't want to, because I play for myself, for fun, because I want to, and not to know everything about the world of Might and Magic. And I was talking about the Heroes 3 campaigns; I didn't include Rion from Griffon's Heart or Roland and Archibald (from Heroes 2). I also read somewhere, though I don't know how reliable it is, that Alamar is some kind of great Lord. To be honest, I haven't even played Might and Magic, but I've played Heroes, starting with the first one, and there are Gem, Crag Hack, Sandro, and Alamar as mages, and I don't remember who made it to the third game among the knights.
P.S.: If possible, please clarify who among those well-versed in Might and Magic lore knows about the leaders of races (I mean those like Enroth, Crag Hack, Brackada, and so on).

Added after 4 minutes
2 XEL: You just misunderstood me; I'm not well-versed in this area; I'm more of a fan of the game than its history, although it is interesting, but I just don't have time to surf the web looking for information and read it, especially in English