You know, I've simplified things for a reason, and I'm going to keep things simple for that same reason. So that hopefully you'll get it.
You can find many examples of tuned, built, blown 2.0L motors putting out big numbers. And then you can go find many examples of tuned, built, blown 4.0L motors putting out bigger numbers because, hey, guess what, greater displacement ultimately means you can burn more fuel per cylce at a given RPM range.
I'm sorry you disagree with, uh, science, I guess, but you're arguing an indefensible position.
You can do some pretty neat things with motors these days. If you take two engine blocks, one 2.0L and one 4.0L and you build them up in basically the same way, fully tuned running 15PSI of boost, sufficient fuel, good AF ratio through the entire RPM range, the 4.0L motor is going to be producing more power. Period. We're talking in terms of potential, here. Take two motors, one smaller than the other, and take them both to the bleeding edge of engine technology, and you already know which one is going to be making more power.
There is a reason why there are displacement restrictions in most racing circuits and why 600cc bikes don't race with 1000cc bikes, for example. Care to guess why that might be?