Sam in no way, shape, or form dominated Ben Wallace in that series. Like Sam, the numbers looked nice, but he made a ton of mental mistakes in that series. It wasn't Cheeks using him away from the paint, it was opposing teams having a gameplan to exploit the fact that Sixer big men didn't defend the pick and roll properly. That was the biggest defensive problem the team had, every team in the league did nothing but set picks on AI and Iggy up top with their big men because Sam, Webber, and the rest of them(minus Randolph)wouldn't flash out to defend the shot or cut of the lane to the basket, they were spectators watching the pick be set and watching the man take the jumper or blow by them.
Sam could be an offensive and defensive force...if he had a brain or desire to get better. His athleticism is frightening, but he can't catch the ball on offense, takes fadeaway and turnaround jumpers when no one is on him and has terrible body control. On defense, he just doesn't have a clue, but to try and block everything.