Haven faction discussion.

Castle. On the screen where you choose a faction, it's the castles that are selected. "Bastion/Rampart" is not a faction; it's a castle. "Castle" is the castle of a faction/country/state in Erathia.
You disagree?

They've always been like that. Except for the Imps.

What do you mean?

Yes, but you can only call buildings or cities "castles," not the inhabitants. And considering that the Heroes series is primarily focused on battles, and building a castle is just preparation for them, it follows that the entities within the castle are united into a faction.
I don't see that with 3-4 heroes; the demons are kind of weak. But I agree about the 5th game; I think the Imps look just as bad as the Goblins in the Stronghold (i.e., not very good).
I'll answer you in a private message.