a quotation from your source:
"The quoted passages support the idea that a well-regulated militia was synonymous with one that was thoroughly trained and disciplined, and as a result, well-functioning. That description fits most closely with the "to put in good order" definition supplied by the Random House dictionary. The Oxford dictionary's definition also appears to fit if one considers discipline in a military context to include or imply well-trained"
but thoroughly trained and disciplined by WHO?? The government, of course,. The alternative is that you have a bunch of yahoos all running around with their own "well regulated" miliitas doing whatever they please, not under the control of the government. Kind of sounds like the situation is Iraq, doesn't it? And I seriously doubt that is what the Founding Fathers had in mind,