I've got 58 non-seniors returning. Lombard is a virtual certainty for a 5Y so let's say 59 returning. That number could rise to 62 (Kendall Moore, Collinsworth and Utupo could all conceivably return) or fall to 57 (we could take none of Moore, Collinsworth and Utupo and lose Tuitt and GAIII to the NFL).
Right now we have 23 commits counting Morgan (as apparently the staff is). So we are at 85 already if everyone comes back, which I think we want to happen; I do, anyway. The only player of the 5 bubble guys that I could take or leave is GAIII, and even he is a real asset on kick returns. We have little experienced depth at Moore and Utupo's positions, Collinsworth can provide veteran leadership and consistency, and Tuitt speaks for himself.
We are still pursuing, and have a decent shot at, McKenzie/Nelson, Juju, Quick, Braden Smith, Alexander, and Holley (per Loy).
I want each of those guys more than Jones. I like Jones, but we are really deep at RB for the time being. Even if Atkinson doesn't return, we've got Cam, Amir, Folston, Bryant, and Mahone back next year, and all but Cam are eligible through 2016.
So the issue here is not whether you take Jones as an 86th guy with the understanding that we always lose somebody. It's whether you take Jones as a 90th guy, expecting to lose 4 or 5. I don't think you do. That's just too risky.