Brady couldn't win a ring when his teams weren't good enough, that's why he doesn't possess 22 rings right now. He couldn't win last year with basically the same exact team. Winning a ring is hard, repeating is even harder.
No Godwin or Brown... not basically the same team at all.
You need at least "average/good" (Flacco, Dilfer, Foles, Brad Johnson, Hostetler, Doug Williams, Jim McMahon, Eli Manning, Mark Rypien, Jim Plunkett, Peyton Manning with a broken neck) QB production.
Look at your list there...
Flacco was otherworldly in the 2012 postseason... he carried that mediocre team on his back in the postseason... 11 TDs, 0 INTs and a passer rating of 117.2.
Eli Manning did the same for the mediocre 2011 Giants... 9 TDs and 1 INT in the postseason... took a beating in the NFCCG and responded heroically.
Doug Williams threw 4 TDs in one quarter of the Super Bowl... played a great game.
The 2000 Ravens are an example of a great defense carrying a mediocre team to a Super Bowl title.
Same with the 2002 Bucs... great defense, mediocre team.
The '85 Bears... the greatest defense of all-time... offensively they basically run it down your throat but their primary objective was don't screw it up and let the defense win the game.
You're saying average QB play on great teams is good enough to win but you're not giving entirely accurate examples... I pointed out 2 QBs who played great for mediocre teams and 3 all-time defenses who carried otherwise mediocre teams to titles.
The 2015 Broncos by the way weren't even getting average quarterback play... Manning was atrocious that entire season and the rest of their offense wasn't doing much either... this is another example of a great defense carrying a mediocre team to a title.
And the fact of the matter with Brady is he gave you uniquely clutch quarterback play and an uncanny ability to comeback from deficits in the postseason...
1. Game-winning drive in SB 36.
2. Overcame 4th-quarter deficit and led game-winning drive in SB 38.
3. Overcame two 14-point deficits, a 4th-quarter deficit, and led a game-winning drive in 2014 Divisional Round.
4. Overcame 10-point 4th-quarter deficit and led game-winning drive in SB 49.
5. Overcame 25-point second half deficit and led game-winning drive in SB 51.
6. Overcame 10-point 4th-quarter deficit and led game-winning drive in 2017 AFCCG.
7. Overcame two 4th-quarter deficits and converted three consecutive 3rd-10s on game-winning drive in OT of 2018 AFCCG.
8. Game-winning drive in SB 53.
Brady has 14 postseason game-winning drives... second is 6.
Brady has 9 postseason comeback wins... only one other QB has more than 4.
That's what it takes to have more than twice as many postseason wins as the next QB.