As I seem to recall, the first part of the second amendment reads "A well regulated Militia, being necessary to the security of a free State...". From what I read "well regulated" at the time the 2nd amendment was written meant in good working order. Does that not mean well trained and well supplied?
What the founders were saying was that (despite many arguments to the contrary at the time) it turned out that a standing professional quality military was going to be necessary to protect the growing new nation. But that unlike the life they’d just led under the British crown, the existence of such a well-regulated force could not be used by anyone in government as an excuse to infringe on the individual right to keep and bear their own arms. The 2A doesn’t establish a militia or set any standards for the personal possession of arms. Exactly the opposite! It says your right is protected even if there IS a local, or state, or national militia.