I think that's the same thing...you can use what you're used to...and if if have to use something different under pressure, you are more likely to make a mistake.
I believe that was the point, rather than what IN PARTICULAR works for an individual.
One thing we see all the time...some UI, and techniques, etc...work great in some contexts, but in other contexts, OTHER UI or techniques are better. Those who use ONE context, feel THAT UI/Technique set...is "right". So we constantly see several people who are ALL right, who all disagree with each other.
I DO see a bit of over dogmatic references to the loss of fine motor skills....It does happen, but, its not like getting hit with a curare dart every time you're in a conflict. I'd say its more like a proportioning of the body fight or flight resources, than completely losing the ability to use a particular set of muscles.
Part of the problem might be the SELLERS of certain equipment, who have a VESTED INTEREST in propagation of certain dogma...making sure that people THEY TRAIN are spreading that dogma.
If you sell a product that requires a user to do ABC, and a competitor has one that only requires you do to AC...you make DAMN WELL SURE that B is VITAL, and that leaving it off risks life and limb, or durability, or whatever you can throw at it.
Its not hard to do that really...Just the afore mentioned Glock/Safety issue - "Glock Leg" and other popular stories.
Its not GLOCK making sure you heard about the guy who pulled the trigger pulling the weapon shot himself in the leg, or coined the phrase....its a competitor...with a vested interest in making SURE potential Glock buyers know that "Glock Leg" is a liability (That it can BE a liability issue, or that the time lost to WORK a safety can be, is not the point..)
Same with lights...Surefire was making damn well sure "That primaries were the only batteries for ANY weapon lights" as a dogma...until of course SUREFIRE had rechargeable batteries to sell....for their (Now able to run on rechargeable) weapon lights.