Tom Brady is nowhere near Joe Montana. The ONLY thing that puts him in that conversation is the SuperBowl wins ans Bill Bellichik is more responsible for that than Brady is. Brady's kicker won them games. Joe Montana threw TDs for the win. Matt Cassell's success last season showed the system in place is responsible for much of the success in New England.
Peyton Manning does more than any QB in the league, or in the history of the league, actually. Brady can be replaced by guys who haven't taken a snap since high school. Take Peyton out of Indianapolis and the Colts are immediately a bad team.