How did "well regulated militia" come to be interpreted as any individual person? It fascinates me that the most pro-gun rights people tend to be the most constitutional literalists. A single person is literally not a well regulated militia.
Keep in mind that "the militia" was the citizen body, comprised of those (often) self-armed individuals. Quoting from William Hogeland in Autumn of the Black Snake (2017):
Technically, the militia was the entire able-bodied, free, white, male citizenry, sixteen to sixty years of age, obligated to serve in the defense of a province. Often self-armed, though also armed and provided with ammunition from public armories, and trained on a regular basis by officers elected, up to a point, by the men, each member of the militia stood ready to serve without pay as a soldier when needed, then return to ordinary activities when a treat was repelled. (126)
The British would often recruit and draft from the militia (and they called it as such).
The British commanders would refer to these paid, provincial forces as militia only because they'd been drawn from the obligated, supposedly trained force of citizens. (Hogeland, 127)
So at the time there wouldn't have been any contradiction between saying citizens had the right to keep and bare arms and a militia is necessary for defense.