People using iron sights could use them differently, 6 oclock hold versus center hold for example, but any two people who correctly use the same hold will hit the same spot.
Scopes are even simpler. If you're looking through it without parallax and you have your eye correctly centered in the optic, you can't help but hit the same spot. Optics only work one way.
Still happily answering to the call-sign Peetza.
The problem, as you so eloquently put it, is choice.
He is no fool who gives what he can not keep to gain what he can not lose.
-Jim Eliott, paraphrasing Philip Henry.