...so...you could NOT have a militia...without weapon owning citizens.
So sorry....you are wrong.
The earlier SC rulings were written when robber barons, and mega-industrialists used Pinkertons and the like to put down Unions.
Besides......in the Million to one chance say China invaded. Citizens trying to fight them out who aren't in the Army wouldn't automatically be in the National Guard. By definition.....they would be a militia.