There’s also a thing where most of the practitioners, including very high level ones, don’t have a clue how it works. They know what works for them, that’s about it. All of it is all intent and the wand and words and other trappings are intended to help channel it but are commonly mistaken as the tools doing the job. They would know this in universe if any of them were even passably interested in the scientific method instead of being arrogant rich bastard assholes that I fully detested by the end of the source material.

A fantastic real life corollary was Jacob Aldolphus “Jelly” Bryce, a prominent, arrogant, and primarily lucky FBI agent who had survived a number of shootouts. His method of ‘shoot your pistol from the hip like a madman’ became official government training for many years until someone did a study and rightly pointed out that the technique only really works if you’re naturally coordinated in exactly this way, which Jelly was. For everyone else it was awful training that lost quite a few lives until actual science could show that bringing the pistol up in line with your eye didn’t take measurably longer and allowed you to hit your target much more effectively.