Some dudes came over here at the start and didn't stick around. For instance, haven't seen Butch Cassidy here in forever. He's still a big presence on RSS. I think you nailed it: familiarity and recruiting database. Plus, there is some decent information there every once in a while. When Nebraska actually is making moves, it's great to have as many sources as possible, too.
The built-in subs is more than enough, I'd say. There are guys who cover the team that I really enjoy, e.g., McKewon, but it's not like they bring so much more credibility and analytical insight that it makes up for those built-in subs. And, like it or not, Callahan is always hustling on this gig. He's one of the most recognized guys among the local journalists.