Fact of the matter is he was frequently the worst forward on the ice for Buffalo. That's on him, not his teammates. The Sabres depth is bad BECAUSE it's filled with players like Sheary. If Crosby can make him marginally useful for you guys, good for you. He's not a good hockey player, though.
Sheary was more than "marginally useful" even when away from Crosby and Malkin. Odd... he was a good hockey player before he went to Buffalo.