You're talking about mechanical defects, not technique.An easy test, take a crappy, gritty, heavy trigger (on any pistol) and shoot for group at twenty five yards, one hand.
Same test, but with a perfect 3lb, crisp release, crude test, but you get the message?
Try your little test with the sights screwed on loose so they rattle around and see what happens.
We of course could go back and forth all day long exchanging mechanical defects - but - the simple answer to that is, if it's a defect - have a smith correct it or get rid of the gun.