If you replace Brady with a top 10-15 QB in the league for 2001-2004 and 2014-2018, keeping the rest of the offensive line, skill players, and defense, how many SBs do we still win?
With Matt Hasselbeck on the 2001-2004 Pats, I think it's not impossible we win in 2003 and 2004 on the strength of the D. 2001 was won on Brady's guts though (with some help from Bledsoe in the AFCCG).
With Andy Dalton on the 2014-2018 teams, none of those teams win. Brady willed us to the first two superbowls. Dalton or an average QB would've won the Rams Superbowl, but Brady went off in the AFCCG in Kansas City to get us there, so we can't even give him that.
So at best, we win 2 titles without him. Of course, we can do the same thought experiment and put Brady on the 2001-2004 Redskins, he doesn't win anything either.