While I don't disagree with your overall sentiment about Brady and the amazing upside it would take to consider replacing him, I hardly think JG is an unknown theory to the Patriots organization. This has been a very common misnomer by a lot of posters who are trying to oversimplify the situation and ignoring some legitimate signs that the Patriots are uncommitted on their future at the position. People are operating under the wrong assumption that BB knows as little about Garopollo as we do.
Garopollo may be the worthy successor the team had hoped for in 2014, and Brady may not demonstrate any signs of regression and continue playing at an otherworldly level. Both things can be true at once, and they most likely are. That's why there is such a divide on this forum and a hesitation from the team to rush to resolve the issue.
I never said Garrapolo was an " unknown" to the Patriots organization, I said he's unproven, there's a big difference. I'm sure Garrapolo has shown that he understands the offense and the reads and check downs etc etc, what he hasn't done is proven he can run it consistently, game after game, week after week, in fact he hasn't even shown he can be out on the field week after week. He's never brought them back to win a game, he's never shown he can adapt when defensive coordinators game plan for his strengths and weaknesses, he's never shown he can rebound from adversity, and he's never shown he can make the big plays with the game or season on the line. I'm not saying that's his fault because he's stuck behind the GOAT , but it's still a fact that he's never proven he can do any of these things, and getting rid of the greatest player to do all of them, especially while he's at the top of his game, is nothing short of batsh.t crazy, and it presumes that Belichick is a total moron, because only a total moron would get rid of Brady to test out whether Garrapolo can do these things or not.