Evil Monkey, I said it, and the adrenaline kicked in, and I am not in a coffin. Neither are any of my mates from similar situations. So, allow me to be held up as the example of the contrary for you.
After a certain amount of experience, it's just a pistol. Look at people at the top of their game, and tell me if they can't immediately adapt to varying equipment. Can Tiger only hit balls with a 3 iron? Can Byron Ferguson only shoot arrows from a longbow? (He can hit airborne aspirin with any darn bow you hand him all day) Can Stewart only handle the wheel and shifter of an F1 car?
It's all silly. Train with handguns if you intend to carry handguns. Never for a second have I second guessed what kind of gun was in my hand or its controls or my ability to hit with it. Never. If other folks don't have that confidence, then they should use what works for them, but after hearing the "same gun, same place, same holster" mantra for decades I just don't agree. I have shot for my life with different weapons and I'm still here. So have countless others. I have a lot of trouble picturing a guy pulling his pistol and fumbling the shot because it's not the pistol he learned on in 1995. If he's going to fumble the shot, in my experience, he would fumble it with any kind of weapon he chose.