I was going to guess Perine's 40 time was clearly behind the other two. Not so. Perine ran a 4.6 and Davis a 4.57, although anyone with a set of eyes can see who the better back is.
Scarlett on the other hand is seriously fast, supposedly clocked at 4.34 in 2015. You can't logically keep a guy like that off the field.
My guess is we see a lot of Scarlett and Davis and not as much of Perine, which would be fine with me. I think after Scarlett, Davis and Toney -- and whomever lines up behind center -- there aren't many touches left.