2001->2004: 3 rings with worse offensive personnel
2005->2008: 0 rings with better offensive talent
Can't blame it all on the defense. The 06-08 defense has been top 10 in the league.
And you would rather blame it all on the offense. In particular, McDaniels. The Pats' offense was #1 in the league in 2007. The Pats defense was average at best this year with one of the worst red zone and 3rd down defense in the league. Let's go year by year shall we?
2008: Pats offense (5th in total offense, 8th in scoring offense), Defense (10th in total defense, 8th in points allow)
2007: Pats offense (first in both categories), Defense (4th in both categories)
2006: Offense (11th in total offense, 7th in points), Defense (6th in total defense, 2nd in points allowed)
2005: Offense (7th in total offense, 10th in points), Defense (26th in total defense, 17th in points allowed)
The Pats defense was clearly below average in 2005 and the Pats' offense was in the top 10 in every major category between 2005 and 2008 except one year where they were 11th in total offense. Also, do you really think Matt Cassel is better offensive talent than Brady? Or Reche Caldwell is better than Deion Branch or Troy Brown in his prime?
So, the Pats offense was in the top 10 as much as the defense during the same period. In fact, the offense was far more consistent than the defense. So by your own logic, you cannot blame it all on McDaniels.