Ever since Jerry Jones took over the Cowboys he has been trying to make something different work - like any manager or executive. You take over the job and don't want to hear about what the last guy did well, you want to look for mistakes, correct them and be the hero. More than 20 years later we are doing the exact thing that Landry is remembered for - the 4-3 Flex.
It's all about freeing up the Middle Linebacker to make plays, just ask Lee Roy Jordan or Sean Lee.
You can see it already in limited snaps in pre-season, 8 solo tackles, 1 assist, 1 strip sack and 1 pass deflection.
I don't think Lee has ever been credited with more than 10 solo tackles in a game officially but I expect that number to go up this year as well as PD's, INT's, FF's and sacks.
The Flex was to counter what the offense was doing to keep the SS or MLB out of the backfield, we do the same thing today with 1-2, 1-3, 1-4 RB-TE 12, 13 and 14 personnel sets. This Sunday we will see the same thing from the Giants, more TE's are being drafted and more are making the 53-man roster. TE's are athletic enough to handle linebackers whereas Guards are not. Why swing a Guard when you can just put a TE on each LB.
We'll do the same thing with the Cover 2 Defense... move Lee back like a Free Safety on passing plays and bring him over the Center for running plays and have him stare down the running back unblocked. If it's Play Action he's the guy to call it out, he doesn't have to worry about covering a TE for that extra half-second and can watch the play develop before reacting.
Jerry tried to get rid of the 4-3 defense as soon as he could but in the 90's he had to win, when it stopped working he was more than happy to bring in another scheme and a Ryan to run it. How many NFL championships have the Eagles won? Garrett brought back the Landry coaching style and the Landry defense with it.
Landry in his coaching days did everything but beat Lombardi and you saw both benefit from working together with the NY Giants. Landry's Defenses were legendary and just the fact that we are going back to 3 linebackers means it has stood the test of time. The firing of Tom Landry will always be controversial - just like Garrett being the Head Coach and Offensive Coordinator - but almost 25 years later the Landry defense is still relevant and it's no coincidence that a Ryan defense was not successful in Dallas.