RB aren't only for physical player. You can get passed the trench with elite agility and elite speed. Thats what Thomas can bring. He'll not be on my HB dive formation all the time BUT, on a shotgun formation, he can do a lot of damages.
Whats my point on the CB, is they are as fast him and most of CB learned all their life how to win challenged catch (catch which can go either way). Thomas is a great receiver because he can run the ball after the catch and he played against linebackers most of the time for the coverage, so I don't think he could be a better tool for a team in a Wide receiver position. But that is just my opinion.