I think Dtown is pointing more towards looking and being in tip top shape shows that an athlete is more dedicated to owning his craft. If you are going to play X or Z in this offense you have to be physical. T.Will isn't built by any means, but is the best run blocking WR we have. He doesn't have natural hands but he sacrificed his body plenty of times in the run game.
Djax is not ripped/built by any means, but he has killer instinct. Much more than Brice.
Also Faulk was one of the 1st RBs of his kind, so that's a tad apples to oranges.