1000 yards is a stupid bench mark, and Harrison wasn't the key back for half the season, he had a few starts played great and got set back down again until late in the season because Jamal Lewis wasn't finished riding out the final muscles in his body.
Wolfe at least contributes to the team when he is out there. Maybe not when he goes into a vikings front line the especially for no reason like in 07 when Benson was actually having a good game... but use him as he was drafted to be and he fills the role. 3rd down and special teams. He had some decent draws when used and several good passes when thrown too, 2 back to back ones the only 2 games he was ever actually used more than 1 series in a game and others leading to good gains or penaltys oddly due to his size when he got ripped on the face.
I'm not a huge supporter of his ability to run at all but he can do more than people throw out there thinking he is worthless.