Teams use different philosophies on a bunch of categories of "special" plays. I'll steal a page from the cap guru's book on this one: more than one strategy can work.
Absolutely no "special" plays... sacks, int.s, forced fumbles, fumbles/recoveries... is bad. It does not logically follow that leading the league in one or another category is good. Obviously recovering a fumble on the 10 yard line has a bigger impact than on the 45. Ditto a sack for 15 yards and a safety versus a .5 yard loss by the QB that goes down as a sack.
Luckily for a team as self-directed as the Pats, more copying goes on in the NFL than down at the local Kinkos, as I've heard it described.
The Giants got to Brady with huge pressure from their front 7... that team was sack happy, no doubt. And we can all replay, over and over, the "hurry" when 3 Pats were after Eli, and he still got off the velcro-helmet pass to Tyree. "IF" we had sacked instead of hurried him, "THEN" we would have won. Uh, unless in emphasizing sacks we would have given up some of the other D that held the Giants to 17.
One thing we know is that the old chestnut that every game turns on a few key plays, is definitely something BB has repeated on numerous occasions. I think you put that together with the focus on versatility, and in very broad strokes the philosophy in NE is to judge matchup by matchup what range of "gamechanging" and "game sustaining" plays are most likely against a given opponent.
You hear that encoded in some of the BB coach speak... every now and then he'll go on a jag about how "____ can do a lot of things, and you know, the more things you can do out there, that adds to what you can do..."
This week we might want to be sack-happy. Next week we might want to be extremely conservative and wait for the mistake. The next week it's time to set loose the ballhawks. Rinse, repeat. Of course since we've been pretty much "on top" lately, the ball hawking has been LESS necessary, more of a luxury. The 2001 game plan against the Rams was all about gambling, taking away Faulk, and playing mistake-free football. Against the Giants it was play your game, don't give it away, and make them take it from you.
Can you conclude that that was wrong? Sort of. What you can conclude is it didn't get the job done. You can not conclude that we should not play a similar game plan in a similar situation, but it would need tweaks. Small sample size dictates that "we win those close ones" may have been a false construct in the first place.
Still the general view in NE seems still to be, not to sell out for any given range of special capabilities, like a LB corps capable of being top 5 in sacks. If we get that ALONG WITH the versatility, fine. I think once again, that's what you see with the selections in this draft.
This also tells you what you need to know about why there's never an "identity" for a Pats defense. There's no "Blitzburgh." There's no "New York Sack Exchange." You might not care if the QB stays clean all afternoon one week, but you might want the pressure the next... and that goes hand in hand with the NE approach.
Just my .02,
PFnV
Belichick has shown that he is not only capable of getting valuable play out of early-30s LBs, they can be play-makers and starters. 
