FK – British troops were known as ‘regulars’ because of the way they were trained to march. Thus well regulated meant ‘well-trained.’
So ‘well-regulated’ militia means they get their fat asses off the couch and get out there and learn the skills, tactics, overall strategies of combat.
Good luck getting the average ‘conservative’ or ‘libertarian’ to develop the backbone or gonads to do that. They can’t even publicly state what must happen if the commie trash or some other statist force ever orders us to ‘turn them in.’