Interesting. You inspired me to google the etymology of the word regulate to see if it used to mean something different. According to this page of an online Etymology dictionary:
regulate (v).
1630s, from Late Latin regulatus, pp. of regulare "to control by rule, direct" (5c.), from Latin regula "rule" (see regular). Related: Regulated; regulating.
While this does not tell us what the founders meant by it for certain, it seems that the original 1630 meaning had nothing to do with equipping but with controlling by direct rule....which is kind of what it still means today.
Still I am no expert on the language of this time, and am open to evidence that the founders may have meant well equipped--outside of opinions expressed by debates of the second amendment, where the interpretation may be colored by one's views.
Good source and here is Noah Websters American dictionary of 1828
http://1828.mshaffer.com/d/word/regulate
regulate
REG’ULATE, v.t.
1. To adjust by rule, method or established mode; as, to regulate weights and measures; to regulate the assize of bread; to regulate our moral conduct by the laws of God and of society; to regulate our manners by the customary forms.
2. To put in good order; as, to regulate the disordered state of a nation or its finances.
3. To subject to rules or restrictions; as, to regulate trade; to regulate diet.
To make sure you know what that's about at least once a year ALL the knights or men at arms in fealty to a specific noble would show up with their arms for an inspection!
In that way the ranks of the nobles would be known to be prepared for duty. Deficiencies would then be addressed.
This practice where the upper and lower ranks of the ruling warrior class came together for inspection is still followed in modern armies all over the world, and in the earliest times was of vital importance. Spartans would recognize it, as would Athenians!
So would the Kshatriya in the Mahabarat or Ramayana.