Given how much of a beating the RB position takes, it seems like it would be wiser to spread that around more than they do.
Of course, the coaches have been willing to give carries to the QB and to various WRs (and even a TE now and then) over giving carries to the 2nd and especially the 3rd or 4th string RBs. That would suggest that they really don't trust McChesney or Ropati to get the job done, but McChesney sure came through for us when the coaches had no other choice but to give him the ball.
I don't understand that philosophy regarding RB usage.