I actually like the idea of having to participate in a large scale battle in a dwarven fortress/mountain as long as it was broken up over multiple quests and the player's participation did not focus on ultra large scale combat.
It's unlikely DDO could handle a large enough number of mobs to actually provide the "army" level of combat experience.
Personally I'm very disinterested in the idea in general. If you want this I recommend playing WoW, lots of large scale battles which you, the chosen one, must singlehandedly win with appropriate crowds for you to stand out from.