I lake the direction of your ideas flow though do not share the idea of turn-based game. Do not turn OC into MMO game, please. Anything we've discussed far to this point was about single-player (cooperative) campaign. So if you want a clash of factions - go choose melee from scenarios pack.
About everything else: random world generation would give a GRAND boost to the gameplay increasing campaing replayability. I always like the idea of having "world map" aside from main game landscape (which can be seen in any scenario)  - randomly generated, yes. Concerning story: it would be good (no, GOOD, AWESOME!) to play for a different (let it be called) "social class" (for example, you choose to play as a king and his army, or as a bunch of rebellious peasants, or pack of pandits or whatever) thus providing a totally different gameplay (as well as, maybe, different possesions at the beginning of the game (king already have a casstle, his warriors are armed with beast weaponry, have horses, etc., while peasants should start with only clubs and axes)).
Again, I think it will be good to have this sort of a campaign aside from traditional scenario packs.