The way I look at it, if I assume the rumor that Kane was promised the DC role in the future is true, then Bielema said, Henry is too good to lose. I'd rather go against my word than lose this guy. To me that speaks very highly of Henry's ability.
People are acting like Kane is some amazing DC around here. If he was as amazing as people are making him out to be, he wouldn't have ever taken a demotion to come to a struggling program in the first place. That is not to say he's bad, he's clearly very good at his job, but let's get a little perspective.
That said, when I look at what made Illinois a great defense, it was primarily our DBs and DL in my mind. If Henry was super close with Walters, surely they weren't always talking about Pokemon and mid strength beer. He's going to have some insights into what we were doing. Also let's not forget our staff included Bielema (ex DC), Buh (ex DC), as well as Kane and Walters both with DC experience. So to think Walters was the sole architect of our defense is not likely true.
I'm the type that says ok you're gone, you mean nothing to me anymore, now who are we getting next. We could go recruiter and grizzled out vet, which is what I'd do. Terry Hawthorne would probably not mind a jump from SIU to his alma mater, and we wouldn't mind an even better connection the best football factory in Illinois.