Well, that's what the "week of bone crushers/berserkers" is – Ubisoft just has a vivid imagination, but the jokes aren't very good.
Ideally, all neutral creatures should eventually become part of some factions. IMO, that would be the right approach, i.e., all the undecided ones – wolves, mummies, etc. – should get their own faction.
IMO, having more factions would be more interesting, but only if they fit into the world of Heroes.
