In my opinion you don't have to have size to be a power forward - you just have to play like you have it. Getting into the crease, the corners, banging bodies, and having at least decent numbers is the image a PWF evokes to me, someone who drives to the net a lot and isn't afraid to mix things up (not necessarily fight though). Can Wheeler do that? Absolutely, and he does it well. But I don't think he does it enough to really be classified as a PWF.