He has a lot of wins because he has a good/great team around him. Put him on the Lions and he would not have 100 wins. Not even close.
It is a team sport. But the season that Tom Brady lead the Patriots to their first superbowl win was after Pro-bowler Drew Bledsoe let the the team to an 0-2 start after 5-11 season the year before.
Team goes 5-13 with one QB (considered good enough to go to the pro-bowl 4 times) then the only change made is at QB and the team goes 11-3 and wins the SB. You have to say the new QB had a lot to do with it.