Thank you for the kind words. As I was reading your response about your thought processes and defense, a light bulb went off for me as well. When it comes to offense/defense on passing plays, for the down lineman the roles are flipped.
Traditionally, one thinks of defense as being where your opponent is coming at you, and you react to what he is doing. A cornerback reacts to the receiver's moves, a shortstop reacts to where the ball is hit, a point guard reacts to what his opposite number does while bringing the ball up the court. On a chessboard, it's 0-0 or 0-0-0. In football, on a running play that still holds true. The offensive line comes off the ball trying to push the defenders back in order to gain territory. But on a passing play, the defensive line is playing offense, trying to breach the castle wall and sack the town. (Side note: in interviews, Deacon Jones, who is credited with coining the term "sack", stated that's what he was thinking about when he first used the term to mean taking down the QB)
If I've learned anything at all about Aikido while reading SSI, that's exactly what happens between offensive and defensive lineman on a passing play. Take the force coming at him and redirecting it away from the aggressor's intended target. Making the aggressor use up energy and tire himself out. For those of us here who are in a certain age range, we well remember "rope-a-dope". Ali let Foreman throw all the haymakers and use up his energy reserves; just protecting himself and biding his time. Anyone who was watching the first three rounds thought this could be a short fight - all Foreman needed to do was actually land a couple of those thundering right hands and that would be it. But Ali weathered the storm, then launched a fast-paced offense at a tired opponent who no longer had the stamina to hold up to the pace.
On the defensive line, while you have (in Seattle's case) four men who are ostensibly a unit, much of defensive line play can come down to one person winning his matchup and breaching the wall. If he gets tired another man can be substituted without a great deal of dropoff, provided you have sufficient skilled depth. So you have defensive coaches wanting to make sure their guys are fresh and going full-bore all the time. That does not apply on the offensive line. The offensive line is much more reliant on teamwork and continuity to ensure no breaches occur; you pretty much never, ever see the O-line guys get a breather. If they come off the field it's with medical personnel walking right next to them.