In today's NFL, teams with Defensive minded HS's that are looking for stud OCs to run that whole unit autonomously are at a huge disadvantage.
Now, with the dominance of the O, top OC's are in huge demand for HC positions. Its gonna be very hard to find established offensive minds to change teams without a promotion to HC.
Defensive HC's now will probably have to be a lot more creative in finding good OC's, which is why its not surprising to me that Lovie is getting a college coach.
But at the same time, its a bigger risk to bring these unknown guys in since the HC needs them to design and implement everything on that side of the ball.
As we saw with Lovie in Chicago, when you have a defensive HC, your team's post season lives and dies with the OC.