I think Pollard would be my number 1 out of that watch list. You've gotta assume he will be a clear-cut number 1 back there.
I know very little about Bonnafon, but from a strict upside play, I feel like he might be the next best. CMac seems like he could go down at any time just based on his massive usage, and it sounds like Bonnafon would be the starter (if anyone has a different feel on that, then I am happy to be corrected).
Guice or Edwards next, but I think that those offenses are a lot harder to predict from usage standpoint.
Then Wilkins and Samuel. I definitely like Wilkins, but Hines would got plenty of play and it seems to me like he is getting a fair amount of RZ work (without looking at the numbers). Samuels, I'm just not totally sold on as a full-time back and Pgh offense seems a bit risky right now.
I think you nailed it here.
I would add that I would have Mattison in a tier above all of these, and Armstead in the same tier as Pollard and Bonnafon. I guess Henderson in that tier as well, but he's harder to peg IMO... uncertainty around Gurley, also uncertainty around Brown, could they bring someone else in (like CJA), will McVay continue ignoring the run game, etc.