I understand you are from Buffalo so I will use small words.
He did hire a real OC, however, if he calls him that Detroit doesn't have to pay him, the Patriots do, so it really isn't very hard to understand. Should I explain using pictures???
$$$$$$$
There you go
He hired two recent head coaches both of whom were with the Patriots before, who are almost certainly more experienced in all facets of the gamet the way the Patriots play it, then some young kid from a college program who is the next great thing.
Most coaches hire OC's and DC's so that when their team sucks and the fans are calling for someone to be fired they can throw the coordinators under the bus and maybe keep coaching a while longer. Bill isn't afraid for his job, no mater what some of the morons on this site think, he is trying to get the best people around him who will help the team win.