Bill Belichick has historically struggled against Mike Shanahan up until that time, but they shut down Mike Anderson that game. But yes, their LB's were trash that season.
However, the secondary was also a major weakness and couldn't hold up.
Pats could barely score 13 on that defense where the scheme was scraped just a few years later after teams caught onto it.
But the question was about Brady's playing badly against inferior teams in the playoff losses. And the answer there is that it never really happened. The closest to it was the 2010 loss to an 11 win team.