1. The Patriots defense was designed to stop top-flight quarterbacks like Andrew Luck and Peyton Manning, NOT a top-flight running back like Marshawn "Beast Mode" Lynch. I can really see Lynch gaining 125+ yards in this game.
2. Tom Brady is only slightly more mobile than Peyton Manning. And we all know what happened to Manning in the Super Bowl last year....
Your first point is a strong one. No real argument to be made.
The second point is at most a partial. While Brady isn’t tremendously mobile in a big way, he is generally enough within the pocket if he isn’t injured. But more appropriately, he is much less likely to be baited into a quick dump off to the defense. Manning has been particularly subject to that - especially in the playoffs.
Even that caveat would still leave a balance towards the Seahawks...except for the overt stupidity of the last week.