In short, even if the Pats were to lose Brady, they still would win the SB, but it wouldn't be the lock if Brady was there.
I disagree with this for a few reasons.
First, you have to consider the chemistry built between Brady, his linemen and his receivers. That doesn't happen overnight and requires a lot of respect for the QB as a leader.
Second, Moss as a weapon is dangerous in large part because he comes up with catches that require a great deal of trust on the part of the QB that you can throw to him in double coverage or situations that common sense would dictate were obvious picks. And those situations still require great accuracy and timing on the throw.
Third, without a strong running game, the QB needs to be a master of the West Coast offense M.O., meaning extremely fast decision making in picking an open receiver and making a VERY fast release on the ball in very close proximity to the hands of defenders. We're talking elite level of focus, calm, defensive reads, timing, accuracy and field intelligence.
Fourth, playoff pressure. Brady has been to the Super Bowl and won it 3 times. Matt Cassel has not. I wouldn't put too much faith in a backup QB being able to handle that after entering the season this late, especially when in his first regular season debut this year he threw a pick. This isn't to knock Matt Cassel's long-term potential, but we're not talking potential. We're talking late-season injury.
We've seen Brady carry teams with mediocre receiver corps', decent to strong running games and bend but don't break defenses to the Super Bowl three times and win it. The team never gives up because they have a lot of faith in Tom and because he calms the entire team with his confidence, and is the master of the 2 minute drill and come from behind victory.
Remove that level of talent, leadership, experience and the intangibles of his well-earned mystique, and you are looking at a very different team. And not one I would give a shot at beating Dallas in the Super Bowl, let alone the Colts in the playoffs. I would say the Colts, including injuries, have a better shot at beating Dallas than the Pats without Brady.