TBH I don't think there would be any cultural difference significant enough between Revantusk and Darkspear, and I think Darkspear already hold teh spirit of the Horde's Troll from wc3 and wc2.
Even Forsaken seems to represent the first DKs from wc2 and the only other 2 units that hasn't been represented yet are the Ogres and Dragons. So, I would love for both Ogres and Dragonmaw Orcs to be playable for the Horde.