This all depends where they are fighting at. If they are fighting on Shimrra's turf, his side wins, if not, Sadow pummels them with debris and his side wins. Shimrra has physical strength that I would imagine to be around the same level as Sadow. Assuming Sadow can't just pummel him with the force, he'll be plenty occupied by Shimrra and the slayer while Luke pwns the Massassi. Again, this is only if they are in Shimrra turf (any place where they are surrounded by Yuuzhan Vong stuff since it won't be affected by the force). Anywhere else, Sadow's side wins.