Here is how i see our running backs - and the key to us winning 10 games versus 7 games:

Ashton Shumpert - He can get a lot of carries, and be productive, but he is not an every down running back that will scare defenses.
Aeris Williams - See Ashton Shumpert
Dontavian Lee - in my mind, this guy is the key. He has the all around talent to keep defenses honest. Keeping defenses honest will free up receivers and give Prescott breathing room (move the chains). It's a lot to ask of a young guy - but he seems poised enough to do it.
Brandon Holloway - non factor at running back. Throw him in on some gimmick plays - get the ball to him in open space and pick up some good yards.

Question is this - will Mullen be hard headed and stick with his more experienced running backs - possibly costing us a tough game or two early in the season before giving Lee significant touches? Or will he not hesitate to throw Lee in if we are struggling on offense?