Brady made Belichick successful and famous. Gene Chizik wasn't worth a crap without Cam Newton either.
Bill had a SB win before Brady, granted as DC of the Giants but that was a hell of a Giants D. Plus the Jets head coach for 10 minutes, prior to recent years, the last coach to do anything with the Browns in the playoffs.
Bill had chops before Brady, was successful before Brady, famous before Brady.
Belichick's record as a head coach in Cleveland was 36W-44L with 1 winning season, 1994, when they were 11W-5L with Vinnie Testaverde. Without TB12 as his starting quarterback he had 2 winning seasons in New England, 2008 when Matt Cassel replaced an injured Tom Brady, and in 2021 after Brady had left New England. Belichick had exponentially more success as a head coach with Brady than he had with all of the other quarterback combined. Brady went on to win a Super Bowl with Tampa, showing that he could win a Super Bowl without Belichick. Belichick might win a Super Bowl without Brady, but he hasn't yet.
I'm sure that there are a lot of NFL assistant coaches with Super Bowl wins, but those are group wins that nobody keeps track of. People who coach sports teams are ranked/graded on their records as the person in charge, not as assistants with much less control over the entire team and the associated outcomes, just like ships captains and business CEOs who are also held accountable for the ogranization's outcomes.
