JM, I think you explained it quite well, better than I could have.
I've had Vega testing as well. There is no direct measure of muscle with the Vega machine. But, you do hold a metal hand held unit and the practitioner uses a metal probe on either a finger or a toe. I think the Vega works on a probability scale. So, when being tested for certain ailments there's a needle meter that reads from 0-100. Closer to a 100 reading indicates 100% probability for something.
Vega testing can also can read the energy of meridians to determine if there are clear pathways and no energy blockage. When I was getting cavitation treatment I had the problem teeth meridians checked via Vega. You wanted a high number and you needed to maintain that number for 3 seconds. This would indicate that the energy on that meridian is flowing as it should be. Mine never budged past 50 or so, despite ozone injections and surgery.... Wasn't til later I realized that the problem was a systemic pathogen that set up shop there. Didn't matter what I did to the area it was gonna come back.