I like Tony Pollard, I think he's a very capable and dangerous back. No he's not the guy that's going to carry it 25 to 30 times a game, nor is the physical enough in past protection. But there's no denying he is a very dangerous weapon to have. "Speed in space wins the race" every running back needs room to run, but not every back provides the electricity and big play capability as Tony Pollard.
As for as the degree of difficulty when toting the rock, that depends on if the block was made or not. Not a good day for any running back when the O-line gets beat.