Some of these (like Mike Cox in ’09) will doubtlessly be considered valid. some of these are functions of small sample size. Some include sacks (Denard).
Regardless, some are just flat out wrong (Cross, Jackson, V.Smith were not great talents carrying the ball out of the backfield,) no matter what the YPC numbers say.
Re: Ty Isaac. We’ll just have to wait to see if he ever gets significant snaps in meaningful situations but I see it a lot like the data from the previous years. If you give 20 carries to Smith or Isaac against an MSU I am pretty confident that Smith would be the more productive back. Just my opinion, but I think Harbaugh agrees.