Congress have no power to disarm the militia. Their swords, and every other terrible implement of the soldier, are the birthright of an American...[T]he unlimited power of the sword is not in the hands of either the federal or state governments, but, where I trust in God it will ever remain, in the hands of the people."
Tenche Coxe, The Pennsylvania Gazette, Feb. 20, 1788.
That's what one of the founders thought.
There is no indication in the article that Scalia is addressing anything other than what type arms an individual citizen can own and possess.
What a “well regulated militia” might or might not be able to do is a different question. I don’t think the founders addressed whether an individual could have owned a cannon or a battleship, which did exist during those days.
And the present day gun control issue is primarily one of what an individual can own.