Moreno and Ingram are probably closer to production. (elbow abd hand) Mathews probably has the best opportunity but (knee) could have problems getting in physically mid-season form.
Ingram (the dude was killin it until the hand injury, don't see why he wouldn't rise back to the top once he's ready)
Moreno (unless Lamar Miller keeps up his current pace then he will eat away carries after Moreno's return)
Mathews (injury history knocks him down on my list, but he should resume the lead back role when he returns)
In all fairness I think they are all about the same value. Mathews is the only clear cut back, while the other 2 are in RBBC's. Hard to compare them all since there are pro's and con's to each. The best way to rate them would be their schedules. Whoever has more of the runner-friendly defenses on their schedule takes the cake.