Wright was technically inherited though they wanted him, and worked to convince him to honor his commitment.
Seldon was more of a project than a true RB evaluation. I think they liked him with the ball in his hands and tried to turn him into something he wasn't, or perhaps wasn't interested in becoming. I guess that is a poor evaluation on where to play him, but I think the jury may still be out on his actual ability. He needs to stay healthy, first and foremost.
Sampson was a stud they identified and signed.
Lewis and Bishop have both shown they can play in limited roles. The next step is growing those roles.
Keith was really the only head-scratcher to me, but he doesn't physically fit the mold of RBs they have used and he never really got much opportunity. His portal landing spot was probably a pretty good indicator of his talent, though.
In hindsight, if you don't count Wright, I guess it is more of a mixed bag than solid proof they can nail that position, so I guess again, let's hope they nailed this one.