If we go down that route, the "militia" in the US is divided into the "organized" militia, which is effectively the National Guard forces, and the "unorganized" militia, which is everyone not in the "organized" militia and are:
> able-bodied males at least 17 years of age and, except as provided in section 313 of title 32, under 45 years of age who are, or who have made a declaration of intention to become, citizens of the United States
So I'm not sure "a rule the you have to engage with the militia" is going to get any better of a reading on the 2nd amendment from an "individual" vs "some group of people defined by the government that aren't 'the People' of every other part of the constitution" perspective.
