Without trying to be confrontational, I am just wondering if you are aware of this fact:
The Giants were the 32nd ranked rushing offense last year.
In addition, there was not a single elite quarterback (besides possibly Romo and an injured Rivers) who didn't make the postseason last year. Meanwhile Adrian Peterson, Chris Johnson, Maurice Jones-Drew, and the usual group of all-pro running backs were sitting at home watching the games on television.
The RBs in the Super Bowl the last five years:
Green-Ellis
Maroney
Bradshaw
Jacobs
Grant
Thomas
Bush
Addai
Hightower
Mendenaal
This is why I don't think Belichick thinks it's important to have a "stud" running back, as they are no longer worth the money they cost. The Patriots will settle for average backs, as clearly the recent SB champs have done the same. Now, back in Elway's day, we were in an era of Thurman Thomas, Emmit Smith, Barry Sanders, Marshall Faulk, etc. where it was important to have a stud ball carrier. The league has changed, so I don't see a big need to have a more run-focused offense.
However, on defense, I agree 100%. People forget about just how good our defense used to be, and during this last Super Bowl, we never really felt comfortable because we knew when push came to shove, the Giants D would step up and ours would fail. We were right.
The last star running-back to play in the Super Bowl was Shaun Alexander in 2005 (unless you count a worn down Edgerrin James in 2008 who wasn't even the primary back.)