May be he really wants to be a HC and not dictate how to run the offense or defense. And when there is a really good one available in the market, why not make use of him. Norv doesn't believe in gadget plays and simply runs a power-offense. I believe the Browns have the right personnel on the OL to run such an offense and when you have a RB like Richardson, it is the most ideal fit considering what Turner has done with Smith, Ricky Williams etc.