For starters, coach Pete Carroll and general manager John Schneider have constructed a roster uncommon for its depth of talent in the face of free agency and a salary cap.
What separates the Seahawks from other great defenses of their era is their cadre of at least 10 players with the demonstrated ability to take over a game.
"Me, Earl, Kam ... we're not just three All-Pro players," Sherman crowed last year. "We're three All-Pro minds."
Their film study, knowledge of route concepts and command of situational football enables them to play at a faster speed than opposing offenses.
Beyond that impressive nucleus, Dan Quinn's defense features another half-dozen disruptive influences.
Defensive tackle Kevin Williams is a five-time All-Pro. K.J. Wright is one of the league's premier coverage linebackers. Byron Maxwell's closing speed and tackling led to the dismantling of Chip Kelly's vaunted Eagles offense in Week 14. Irvin has been a terror coming off the edge over the past month, finally realizing his first-round talent.
That bruising physicality works hand-in-glove with a mastery of fundamentals that results in the league's surest tackling, via a strike zone from the shoulders to knees.
This swarming unit is exceptionally well-coached.
"Just like pitchers throw their fastballs in the strike zone absolutely as hard as they can," Quinn said Thursday, "we're trying to hit somebody in the strike zone absolutely as hard as we can."
In the age of the passing revolution with rule changes favoring the offense, the Seahawks are a reminder that football's essence is hitting.
If the "Legion of Boom" captures a second straight Lombardi Trophy, Bennett won't be alone in his opinion that this is the best defense ever to put cleats on the ground.