while the idea is nice from an alliance point of view.
this aint gonna happen.
personally i think the alliance is gonna suffer a major defeat before the final patch with the raid on orgrimmar. and that there only chance too beat garrosh is with the rebel Horde forces.
i actually hope for it, if the alliance gets a major victory before the final patch there wouldnt be any reason too work toghter and it points towards a truce between both factions so it wouldnt make sense if the alliance would get their major victory.
then work toghter too take garrosh down and then go their serperate ways in a truce till the next expansion kinda makes them work as a team too defeat the burning legion?