That kind of depends upon how you measure it. Prior to Dillon, they really didn't have an upper-half-of-the-league running back. Really, a couple of their starters weren't even the upper half of second string running backs.
What has gotten Brady through is that he is good at BOTH the dink and dunk and the shootout, and several styles in between.
In contrast, Peyton Manning has been in a system that showcases his shootout style, but until last year he couldn't do the "small" game well, and it killed him in the playoffs. He still gets left pounding the turn when he is forced to play the small game...or when he throws a pick from being too aggressive for the defense he's facing.
Most of his career the Colts didn't have a defense that could stop the Little Sister of the Poor. That's why his numbers were so wild some of those years. He was always playing catch up.