Concerning RBs, I think we have to consider that Connor gained half of his rushing yards (514) in the last 5 games of the season. It took him 8 games to gain the other 526 yards. Is that a reflection of much better run blocking by the Oline or a sudden renaissance by Connor? I myself credit it more to the Oline than Connor suddenly becoming a top 10-15 running back. Connor's strength is his size (233 lbs.) which allows him to run over smaller DBs once he gets to the second level.
I still believe that there will be little movement in the RB room by the team. It doesn't mean I believe that there isn't a need to add a second RB that compliments Connor. Look at Detroit with Montgomery and Gibbs. Almost 2,000 yards between them. The team still needs a back with a skill set like Gibbs.