I think you have to be somewhat careful to overlook at all other data and metrics because of team accomplishments.
Joe Montana wasn't a better player than Dan Marino, he just had a better situation around him.
I find it lazy to only focus on winning because so many of those factors are beyond the control of a player. If Aaron Rodgers were on the Patriots for the last decade, do you really think they win fewer Super Bowls?
The Patriots were good with Cassel and Jimmy G. If you take Aaron off the Packers then they might win 2-3 games.
Like when the Colts got rid of Peyton and went defeated. It is a team sport and you can't play both sides of the ball.