I'm going to suggest the armor isn't specific for medics, due to the fact that most of the "Foxes" are sporting heavy blasters (see pic 3).
In our world, at least, battlefield medics usually run around with holstered sidearms, at most - simply because it isn't easy to tend to injured troopers while hauling around a huge blaster.
I haven't heard this suggestion before, so I'll pitch it out there - maybe the "Foxes" are translators?