Warner's taken some awful franchises to the Super Bowl. Without Brady, the Pats go 11-5. How bad do you think the Cardinals would be without Warner? Neither St Luois or Arizona were strong defensively. The offense is what carried them. Brady's NE teams were much stronger defensively.
When you really look at it, I think they can't keep him out, although I too am troubled by his years as a backup and in the AFL.