I agree no RB is going to get the attempts that Howard got.
I guess Nagy had no faith Cohen could rush up the middle, he was certainly underutilized. I don't know why that would change this year.
I think Nagy will ceremonially start with Davis... but Nagy seems the type to not only ignore that sort of tradition, but the way he talks about Monty, and how he looks so far, I'd guess Monty is going to be the featured back very quickly, especially if he does well receiving and blocking. That, and if Davis appears to be stymied at rushing, or otherwise unimpressive. I'd predict Davis will look pretty good, but Monty will appear to have an extra quickness and escape-ability that will lead to more attempts.