With performance cars, we only change one thing at a time if we are trying to improve performance and I would think that would be true with trying to improve the performance of a gun too. That way you can see just how much it improves the gun and how it feels to you. Changing out 2-4 thing, how do you what did what to how it feels and how it shoots?
I believe I understand your post , but I think that it is somewhat incorrect, with cars or guns. For example, if you want to improve airflow through your engine, installing a less restrictive intake system will do it... somewhat. But install a CAI and a less restrictive exhaust and maybe even a larger throttle body and now you've made a balanced improvement. Letting more air in, with nowhere for it to go is inefficient. I believe the same thing goes with "simple" gun mods (although I can can make sure none of them are simple). There are some very talented gunsmiths and engineers that create well thought out "upgrade packages" that even a new gun owner can install and enjoy.
I believe the better approach, with minor gun mods, is to do some research and pick a well engineerred performance "package" that insures the replacement components work as a system to provide the desired effect.
I'm no expert (see my earlier posts regarding my own modification mis-adventures) but because of that experience, I know how difficult or confusing doing a piece by piece mod can be for a novice. Some of the guys on here would be good to go that way.... but not all of us. Going part by part on something one is not very familiar with can be extremely confusing due to unforseen "related" effects that a novice can't diagnose, like the issue at hand here.
Having a go yourself, I think, is also a good thing, within reason. As long as one is realistic with their abilities mechanically, some small mods really help you to better understand your weapon. Knowledge is invaluable.... Just my $ .02