Defense is best measured by points allowed and average drive length, really. The drive length is somewhat subjective, so the only really hard data that is worth a shit is points allowed, as it also has the most tangible effect on the game. Even then, you probably need to take points from turnovers in your own half out of that stat to get a good representation, because only the truly elite Ds can hold out when their QB goes full Romo and dumps the ball on the doorstep.
Anyhow, my main takeaway from last weekend is that the games were way too chippy in general, with the Bungle debacle putting an exclamation point on it. Even the GB/Skins game was somewhat chippy, though it seemed like a sunday bible study compared to the rest of the weekend. That shit needs to be quashed, pronto. Players should not be allowed to argue with the ref at all, except for the captains MAYBE, without getting an unsportsmanlike and laying a hand on a zebra should be good for an instant ejection. If players not conducting themselves like grown men hurts the team more consistently, you will get less shitbag behavior tolerated by coaching staffs. The issue is that teams have been getting away with this shit for a while so some coaches are actually INCITING it as a strategic thing, so an instigator penalty is probably in order like they have in hockey. Basically, I am tired of watching teams work the refs and sneak in cheap shots.