Hell, you can't even drive a car across a reasonably sized town and recall how many times you stopped, changed lanes, and so on because it's so automatic.
Once you've learned the how to and done it with a variety of firearms, those skills are set in concrete.
You're right, but that doesn't actually back up your point.
Almost all modern cars run the same turn wheel to the right, turn right. The same goes for pointing and firing a gun. I can drive most any car across town without thinking, and I can hit the target with most any pistol. Point, aim, and squeeze.
The trick comes when you consider controls. One of my cars is American, and has a steering column-mounted shifter. The other is Japanese, and has an automatic shifter between the seats.
Guess what happens when I drive the Acura after a long spell in my Chevy, and go to shift from drive into reverse? I reach up to the steering column, and say "damn".
(A similar thing happens when I switch between countries that drive on the other side of the road. I'll reach for the gearshift and slam my arm into the door.)
That's a mild annoyance with a car, but when it comes to taking the safety off a Beretta versus a 1911, or hitting the mag release on a Walther versus an M&P, a "misplaced habit" can kill.
That is why it's usually recommended to not switch carry guns like you change your clothes. In the stress of the moment you'll reach for the wrong safety, or screw up a mag change.
By all means carry a whole family of Glocks, or a bevy of 1911s
or even switch between categories that feel totally different and are less likely to trip you up (revolver vs. service auto)
even occasionally swap to a simpler gun (it doesn't matter if I try to swipe the thumb safety on a wondernine, but the average Glock shooter would get a real surprise using a 1911 under stress!). Just be careful about building habits that will be confounded when you chop and change.