Do you have a source for this? My understanding of the second amendment comes from reading America’s Constitution: A Biography by Akhail Reed Amar. I’m trying to find reference to this meaning you cited, but coming up short. I also don’t find it in the article by him in The New Republic:
DC vs. Heller settled the meaning of the term in regards to Constitutional law. There's also a long history of "well-regulated" meaning well-equipped, in proper working order, etc. in English going back hundreds of years.
(linking to that site rather than its source since the source is sending a bad SSL cert)
There are other writings by the Founding Fathers from the time of the ratification of the US Constitution reiterating the need of a right for people to own arms in case it's necessary to overthrow the government, specifically including the government they had just created.