Dear ...huh? The fact that the educated Mr. Madison used the absolute ablative in his sentence structure does not make the first clause any less pertinent or applicable, and the word is "the people", not "the individual". Last time I checked, people was the plural, meaning that in a community, arsenals could, yea, should be kept. That is one interpretation that is put forward by serious thinkers on the matter,e.g. Garry Wills, who is anything but a "knee-jerk", sorry, reflexive "liberal". Sadly , that is not the prevailing view at SCOTUS.
As well argue that the Preamble, you know the one that begins, "We, the people of ther United States of America..." is irrelevant in the interpretation of the rest of the Constitution.
The whole amendment is only that one sentence, badly written though it might be, and thus all of it is very much to the point. I'll leave aside for the moment the realities of arms in the early Republic, save to ask if you've heard of Shay's Rebellion or the Whisky Rebellion, the one under the Articles and the other during Washington's administration and the general sentiment about them both.
BTW, the screen name is a tribute to my grandfather, a freight and passenger conductor on the NYC, the guy they called "the brains" in the argot of the era.