I feel like the real X-factor for guys like Rodgers, Brady, Manning, etc... is not only that they are able to assess/diagnose the game at a very high level and figure out the correct approach, but they ALSO have the physical tools to do what needs done with that knowledge, know what I mean?
There are a lot of guys who are physically gifted enough to make "NFL throws"...but might not be able to process the game at a high enough level to utilize those physical gifts when they need to be used.
In the same way there are a lot of guys who understand the game really well, have no problem processing that information quickly, diagnosing coverages/routes, etc and figuring out what needs to be done...but for one reason or another lack the capability to utilize that knowledge in a meaningful/impactful way.
For instance, a lot of the guys who are on the media shows or have a social media presence or whatever...a lot of them put on a persona for the media or play up stuff for hot takes, but a lot of those guys really know their stuff. I think of like JT O'Sullivan, Dan Orlovsky, even our own Kurt Benkert, all of whom were pretty mediocre NFL QBs but all know the game inside and out, guys like that are able to read a defense, assess the play call, predict how things are going to play out, etc at a level that most folks will only dream of. But for one reason or another they just didn't have the complete package to make it all work at an elite level. (I am also reminded that all these guys were in all likelihood probably the best football player their hometown/high school has ever seen lol)
But yeah, anyhow, for me that's what really makes guys like Rodgers and the others mentioned to be the best of the best of the best. It's one thing to know what to do, it's another thing to be able to actually do it in the heat of the game