You've just described nickel. Capers doesn't play nickel for his health, he's just following the same basic blue-print the entire league does: 1WR=1CB. As modern offenses trot out 3WR as a base offense, defenses have to counter with nickel as a base defense. It's simple math. Now, depending on down and distance, there is some wiggle room, but generally defenses will only add more defensive backs, not fewer.
And where do we find these good pass rushing defensive linemen? We have Daniels and maybe Lowry. Clark isn't much of a rusher. Which is kind of why we roll with the front 4 we do in nickel. Those guys are, at least in theory, the best rushers.
Actually, the 3-4 is the better run defense. After all, those three d-linemen are all d-tackle or bigger. The secondary strength is flexibility and having more specialists. Ie, that 2-down run plugger NT, the 3rd down pass rusher but not a complete vulnerability against the run NT....
And where are we going to find those guys?
We don't even know if we have an average secondary yet.
Right. Of course. The entire NFL, with its statistics, knowledge, and experience is wrong and you're right. Couldn't be that every time a a coordinator tries to run a blitz-heavy scheme, he gets destroyed. Even the might '85 Bears fell to the upstart Miami Dolphins...because they were a pass-first, quick passing team. And the 46 defense has faded from memory, the useful parts scavenged, the rest of the carcass left to rot.
Pressure, yes, but not via extra rushers. Even Rodgers gets it wrong sometimes and will get blindsided. But good quarterbacks want to be blitzed for just the reasons I've outlined. You've weakened coverage. Let him identify the hot receiver, hot route to a 1 or 3 step drop, plant, and throw.
Rodgers struggles when the front 4 can get to him and back seven can play Man-2. Extra rushers has very little to do with it.