The big problem really isn't Ross or philbin or aponte, none of that is a huge deal. It's a business structure that works for lots of companies, and it's quite common for a lot of companies to maintain there talent when hiring new bosses.
Here's where the problem lays:
Your trying to hire a outsider who doesn't want to end up being on the outside looking in. Gaine, aponte, Ross, philbin, all already have established relationships with one another. Imagine being the outsider coming to tell them what to do, it's not easy.
And unlike in most businesses where a CEO, if he loses his job, almost always finds himself a great job immediately after, gms may have one chance at it, if they aren't already establishes. In the NFL, it use to be rare to see these guys turn down top notch jobs, over the years that's changed. These top candidates are more willing to wait it out.
So really, the problem lays with insecurity among candidates more than anything else. I really can't blame them either, but I also think ross can make this work, assuring the candidate that there position is exactly what it is, and the staff is all on board is a big part of it.