[K]

I always felt that the turn limit represented the fact that the defender owns the province, so when the attacker fails in a tactical strike to kill the defender's armies, the defender rallies the peasants and smashes anyone remaining in the province.

That being said, my most unfortunate turn limit battle involved a 200 marble warrior army backed by Will of the Fates cast by that one artifact sword. I slaughtered hundreds without taking any losses, but not enough before the limit ran out and I lost an army worth hundreds of gems.