I can't speak to that specifically, but there is a philosophy. Read a great article years ago that discussed the integration of the guard and reserves into the the total force concept. Vietnam was so unpopular that the DoD decided to integrate key pieces of any long term sustained military capability within the guard/reserves. The desired effect was to force civilian leadership to accept that war wouldn't be fought and only seen on the telly at dinner time. The hope was that introducing an airline pilot, a mechanic, a baker, a fireman, etc taken from the local workforce might reduce the potential for long term conflict.
This isn't intended as a kick off to a political discussion, just some insight of the author (a 3 star) into how the guard/reserves evolved from weekend warriors to an intergal part of the day to day operations of the military.