I imagine a good OC with a great QB makes for a lethal combo, as a competent OC can mix in plays that compensate for more average WRs, and a very good TE is a duh help. I suppose if the OL is porous if can render a great QB somewhat impotent.
I heard the term "Cover Zero" from the Dawg QB, I had not heard that before, I understand the meaning, I'm not sure why the term had escaped me, maybe they just call it man to man otherwise? He was commenting that Miss State was in Cover Zero fairly often and that is why he went up top (duh).
To go back to this, cover zero simply means no deep support. No players are tasked with either deep zone responsibilities or deep support for the corners in M2M coverage.
However it wouldn't be clear to also just call it "man to man", because in multiple defensive looks where you have deep support you're also in man to man on all the underneath receivers.
If you're playing "Cover 2 Man" you have 4 pass rushers, 5 underneath pass defenders each with man responsibility, and the two deep safeties to offer deep pass defense support to any defenders that reach that level, each with one side of the responsibility. But because it's man coverage, any underneath defender is expected to run the deep route with their man.
Whereas if you're playing "Cover 2 Zone", your 5 underneath pass defenders are going to have purely a shallower zone responsibility. They pass any vertical receivers to the safeties, rather than follow them.
I'm not sure you see a lot of cover 2 zone these days against modern pass offenses. It has an issue that you're vulnerable in the middle of the field, and thus if your two outside receivers are running fly routes while your slot or TE is running seam, you've got a big hole open. So you'll often see the "Tampa 2" where you show cover 2 and then send a third cover defender (perhaps a speedy LB or nickel defender) to the middle of the field while the safeties take the sides, or you just play a Cover 3.
Problem being if you show Cover 3 you're alerting the QB that you're probably in a zone, whereas if you show Cover 2 it can go either way. Hence the Tampa 2 which is a 3-deep zone but at the snap shows as Cover 2.
And of course, if the defense is showing cover zero you know they're in M2M, so if you trust your receivers in one on one matchups you take a lot more deep shots.