They learned their craft from the likes of Andy Reid and Jim Johnson, worked with eventual Super Bowl winner John Harbaugh and went to the Super Bowl together as coaches for the Carolina Panthers in the 2015 season.
So whenever Buffalo Bills coach Sean McDermott and his Washington Football Team counterpart, Ron Rivera, get together, it's a big deal. Like Sunday, when their teams meet again at Highmark Stadium.
Both men are wired similarly, believe in the same core values and have built their teams with the same principles that include experienced assistants and players who must fit a specific culture.
"You think about the people that were on Andy's staff," McDermott said. "I mean, the list is long of guys that have gone on to have successful NFL careers. A lot of whom have become head coaches, Ron and [Bills defensive coordinator] Leslie [Frazier] to name just two of them.
"I was, as I've said before many of times, just very blessed to be on a staff like that, not just with great coaches, but great, great people, led by Andy, of course, and to learn from Leslie, and Ron on the defensive side, Steve Spagnuolo, Jim Johnson. [Baltimore Ravens coach John] Harbaugh was on the defensive side for a little bit as well. So yeah, just an incredible opportunity for a young guy back then."
McDermott, Rivera, Harbaugh, David Culley (Texans) and Matt Nagy (Bears) are the NFL head coaches today who have served under Reid, who also was on the same Green Bay Packers staff as current Las Vegas Raiders head coach Jon Gruden in the 1990s.
Spagnuolo (Rams) and three other Reid assistants — Pat Shurmur (Browns, Giants), Todd Bowles (Jets) and Brad Childress (Vikings) — also have been head coaches in the league.
"I think it really speaks again about Andy and the people he developed the coaches he developed, what he taught us, what Jim Johnson taught us as well on the defensive side," McDermott raved, "and just the culture that we had in Philadelphia under Andy Reid and the types of guys that we had."
Rivera tops that list, as far as McDermott is concerned.
"It's one thing to be under a great leader like Andy, a great mentor," McDermott said, "but also to take the time to study and take the notes to spend the extra time that I know Ron did to prepare, that's another level."
McDermott, in turn, learned from Rivera after Reid surprisingly fired McDermott but helped him land in Carolina as Rivera's defensive coordinator.
There, they helped build a unit that made it to the Super Bowl in the 2015 season before being upset by the Denver Broncos, another team that was interested in McDermott after he was jettisoned by Reid.
"A lot of it is our upbringing in the league," Rivera said, "and I think that's very important. When I got an opportunity to have Sean on my staff in Carolina, the one thing I told him, I stressed to him is, `hey, let's build this ourselves.' And I was very fortunate to have him as long as I did, because he did a heck of a job.
"To me, the proof is in the pudding. I mean, we started with Andy, we learned his way of doing things and we've stuck pretty much to it. Now we've added our own tweaks and personalities to it, but the bones of it, the infrastructure, you can trace it all the way back to Coach [Reid]."
In the case of McDermott and Rivera, familiarity breeds the opposite of contempt.
All you have to do is look at how many ex-Panther players (and coaches) there are on the Bills' roster.
Said McDermott: "My respect for Ron Rivera has grown exponentially since becoming a head coach myself."