If there was going to be a downfall it will be Entz himself. He isn't Bohl or Klieman - a bit rough around the edge, imo. Roehl is a massive dropoff at OC compared to previous OC's they have had (minus Polasek who was a meathead himself).
But any issues will probably take a few years to arise because of the talent level already in place. It's not hard to win games when your roster is better than your opponents, which is recruiting.