My biggest concern going forward is the length of stay for some of these new additions. I can't think Diaco's life long ambition is being the DC at Nebraska. On one hand, it's good if we see staff attrition because that generally means things are going good. However, it's also difficult to replace top coordinators. Saban fights this every year, and it pretty much cost him a NC this year. Meyer has been trying to find the replacement ever since Herman left. Bill Snyder has been faced with staff attrition ever since he took over at KState.
I was and still am a big fan of the hiring of Riley. I like the direction of the program and the people he's bringing in as either players or staff. However, I'm a little uneasy when looking five or so years into the future.
Diaco has already dabbled some as a HC, unsuccessfully, so maybe he has come to the realization that DCing is his true life's work and will stick around w us for a piece. Assuming he does well, of course.
As to Urban, I'm a bit surprised that he didn't offer Tim Beck the full OC position, because that's why Beck left, to become HERMAN's OC @ Texas. Beck wasn't good enough for NE Fan, of course.