Sorry folks but I'm butting in again with "contrarian" opinions. The view has been presented in favor of another RB in this class, defended by an argument of what if two of our four backs get hurt? [Wood & Gray in the example].
#1]. I believe that this wouldn't shake Kelly up much, in accordance with his next man in philosophy.
#2]. I believe that Kelly has good reason not to be shaken should this occur, because the two backs he'd have left are terrific talents, and Kelly's spread allows a good back to shine without being a workhorse. If Roberson and McDaniel can pick up the blitz, we'd be fine. This is also no excess workload as neither of them must carry the return duties, since we have plenty of other people who can do that.
#3]. Imagine yourself as Kelly in practice the week after the second back goes down. You're standing there looking at TJ and Goodman holding down one receiver slot, Floyd and Daniels holding down another, and Riddick, AIII, AND Toma holding down the slot---with Smith, Collingsworth, and Bennett itching for some time---ALL good to great talents. Hmmmm, you think, I wonder if AIII would like to tear it up a little from RB??? Betcha he would.
The point is of course that Kelly is building a roster of flexible talents and a staff who can use them. In the injury scenario, how many teams would be suicidally depressed about having to go with someone like little ol' AIII as a THIRD back???