I really like this idea and support it, but I would definitely think that this is prime material for an expansion pack. I would definitely put in all the base factions before we start looking at cultures. But with that in mind, what kind of cultures can we imagine for each race? I can see Humans being subdivided into High, Viking/Barbarian, and Nomad, and we've talked about Dark Elves having both darkness/spider/underworld and sea-faring/pirate cultures. What of the Undead, the Dwarves, and the Elves?