Okay. I'll give you that, as long as you affirm that the question of how you do that is, at best, complicated, and confounded by filters and barriers.
usually ones that are promoted from within the organization
Don't know about "usually," but yes, it's not unusual. And to your point maybe even stronger... you have guys who start here, and go somewhere else and seem to be doing well in their most recent gig... I'm thinking of someone like a George Edwards. So, you know the guy already, have high regard for him, have insight into his strengths and weaknesses, and so, could be intrigued to think about him coming back to take a bigger role than he's had here before. (I emphasize...
like a George Edwards... not necessarily him in particular.)
Here's a name. Just spitballin. McCarthy had the same D-line coach most of his years in GB, Mike Trgovac. So, someone McCarthy has great familiarity with and confidence in. Not young, but at 60, not old either. Is he DC material? How would I know? I'm just sayin, yes there no doubt could be some under the radar options out there that could get consideration.