II understand what you are saying, but have to disagree a bit.
A lot of shooters " Crawl " the stock, mounting it to their shoulders, and then lowering their heads to the stock. Sometimes they have to crawl the stock because the Length of Pull is too long. Sometimes they crawl to lean forward, and avoid the toe of the stock from stabbing them in the pectoral muscle.
This puts tremendous stress on the neck muscles and forces the eye to look out from under the eye brow, and, typical, the corner of the brow and nose. Both stresses cause the brain to want to get out of that position as fast as possible, and as you continue shooting like that, the muscles don't want to go back to the same position.
That makes consistency in pattern placement next to impossible over more than a couple of shots. Hunters often don't even notice this, as they fire so few shots, and are more willing to accept misses given all else that happens when a bird flushes.
Competition shooters do notice these things, as they fire lots of targets in a day, demanding the best of shooting form to succeed at end of the match as well as they shot at the first target.
For the stock crawlers, getting them to move the head back will also often cause the stock to move down on their cheek and jawbones, so that the eye is Higher than it was, without any physical change to the comb. It doesn't take much movement for the patterns to rise.
Most flinches cause the shooter to shoot over the target, because he lifts his head up off the stock in anticipation of recoil slapping his cheek. When he lifts that head, his forehand lifts the muzzle of the shotgun, too, and that is how the overshot miss occurs.
For years I have shot a stock that has too little drop at heel, and about half the stock ends up above my shoulder. I use it because it had the higher comb I needed to get my patterns on rising clays. But, when my custom Fowler was made, the additional drop at heel was done, and putting that gun to my shoulder feels like putting a well loved, and used glove on my hand. I can mount that gun with my eyes closed, and when they open, I am looking down the center of the barrel, and the front bead is aligned with my low rear sight.
I still see lots of good shotgun shooters mounting their guns low, and bending their head down to crawl the stock to shoot. They practice endlessly, and burn up a lot more shells than I have time to shoot, or afford. They are very good, but they only occasionally actually win a match.