On the Panthers, I was talking about from 2001 to 2002. In 2001 Peppers wasn't in the NFL. In 2002 he played for the Panthers. Not crazy, and actually quite factual if you look it up. Since Peppers has been there, they've been a top 10 defense 5 of the past 8 seasons, and I guarantee that will stop once he's gone.
Vikes D had too many other good players? Exactly, they had a great D-line with Jared Allen and Kevin Williams, both of whom are much more important than safeties.
The Steelers defense is most certainly not simply Troy Polamalu. There was the defensive player of the year, James Harrison, a young LaMarr Woodley, and very underrated Casey Hampton and Aaron Smith.
And why do you care so much about interceptions? They're a result of the offense screwing up more than a good defense. The Packers led the league in interceptions, partly since 6 of them came courtesy of Jay Cutler. In other news, the Bills, Buccaneers, and Titans were top 10 in interceptions and I'd hardly call any of those defenses great.