Correct here.
1/2 right. Yes, it might collapse the pocket. But if you aren't threatening around the edge, the QB is not under duress. Edge rush + Interior rush are related.
If all you have is edge rush, the QB can step up. If all you have is interior rush, the quarterback can just drop back a little further and/or escape contain and again not be threatened.
So, when I read that, all I hear is: Step 1, steal underpants, Step 3, profit. And no details what step 2 actually is.
Yes, those three linemen + Perry and Matthews in base is an excellent run defense. That's kind of the point of a 3-4--you play bigger linemen to clog up the middle and play two ends. Ideally, the front 5 in a 3-4 is bigger than the front 5 of a 4-3 in total. We get to 5 in each by comparing including 4-3's SOLB and both 3-4 OLBs.
But again, one passing downs, those bigger, slower guys are at a disadvantage. Across the board, NT, DT, 3T, 5T, 7, Wide9, the pass rusher will be smaller than the run stuffer. Bigger is great in the run game, when the defense wins by merely saying, "No, you move me." Pass rushing is attacking a gap. And rushing the passer is more tiring. Dragging that extra weight will tire guys out faster.
Compared to OTs, that weight is an advantage. An OT in pass protection is catching. He uses that weight to anchor and he doesn't have to move as far, for as long, or as quickly. OT is largely about efficiency of movement.
A sideline to sideline linebacker isn't going to help in pass rush.
It's not that I don't value the power, it's that compromises have to be made. Friction is a thing, budgets are a thing, etc etc.
I would prefer 300 pound DEs that can run a 4.5 40. But those guys are somewhere between "non-existent" and "stupid rare." I'd happily have a prime Reggie at EDGE in any scheme. Ditto Peppers or JJ Watt. But there are only so many of those guys period, let alone those guys playing at the same time, let alone on the same team. So you start to compromise and optimize: take what is shown to be useful at each position and be willing to give up what isn't strictly required.
Interior linemen are bigger to take abuse in the running game. They also tend to be shorter, in the hopes they have better leverage against double teams. Speed isn't generally important at all. This gets more and more extreme the closer you get to the center. A 0-NT will be the biggest, a 1-NT might be a little smaller, 3Ts regularly slip under 300 pounds. Also, you need to adjust your weight preferences in general. Your talk of 320, pass rushing DEs is crazy. The only one I've seen close to that was Pickett in 2010. And he was no pass rusher--he was a run-down blocker eater. 280 is huge DE in 4-3 schemes.
As you get further away from the center, straight weight isn't as important, because the job changes. Outside contain, keeping the quarterback in the pocket, and getting your hands up in the air, makes length/height more important. Part of that is also how rushing works on the edge vs. the interior. Interior rushing is wrestling, the outside it boxing. OTs, with the long arms and kickstep can neutralize bigger, slower players from the second the ball is snapped. Inside hands is the key. If the OT can get to your chest plate, he's won. If you're 320 and 6'1", you likely have some stubby arms. He's 315, 6'5". Get that chest plate, lock arms, and that rusher won't be pushing a damn thing. Size be damned. Thus, you want your EDGE guys to also have long arms to counter the OT's long arms.
More dead-horse beating: But Matthews is the typical size of an EDGE defender in most any scheme.
Von Miller: 249. Clay's bigger.
Khalil Mack: 247. Clay's bigger.
Demarcus Lawrence: 250. Clay's bigger
Justin Houston: 258. Willing to call that Equal?
Melvin Ingram: 265
Chandler Jones: 260
Jadeveon Clowney: 267
Ryan Kerrigan: 260
Carl Lawson: 260
Bosa: 276.
Everson Griffin: 273
Brandon Graham: 269