What division of all the factions in the game would you suggest?

Unfortunately, I don't know enough about the internal structures of all the factions except the Enrothians and Erathians...

because I played "The Restoration of Erathia" a long time ago and I can barely remember it now.

Of the games I've played recently, I got halfway through Might and Magic II, and I completed the "Life and Strength" campaign in Heroes of Might and Magic IV and the Haven campaign in Heroes of Might and Magic V.

It depends on what we're dividing.

If you mean the social structure of each faction, then your definition isn't quite right.

If you're trying to define the game mechanics, then it's true that there are heroes and there are creatures :) but that's obvious.

(I've also been thinking, we need to categorize the huts of seers, witches, and other similar structures somewhere.)

Added 4 minutes later
And there's also the player (as a kind of divine intervention :))