I can see Glenn being a successful HC if he takes the Dan Campbell approach. Everyone I know who has worked with Glenn loves him, which says a lot about his character.
Agreed. I don't see him as a HC you hire based on what he can do on one side of the ball. You hire him if you want a CEO coach like Campbell that motivates the team and runs things while letting his coordinators run the offense and defense. But, I don't know if that is what he intends to do and even if he does, I'd prefer a offensive HC and if it's a defensive HC, I want someone that is a better DC than Glenn.