There confirmation of the medic carbines.
I guess it's also prudent to preface my comment as being a snapshot in time, loadouts and equipment varied wildly during our total time in Afghanistan, I can usually tell the tour based on the location of uniform pockets, patches, and general gear.
A carbine was a rather uncommon item during the first few months of my tour in 2006, but looking at later tours they seem to be quite prolific. Short barreled C9's; during my time the only short barrels were "field modification" or otherwise obtained, but on later tours there was actually an authorized short barrel issued.
Uniform pockets for example are found in 3 major variations, during the tours. 2 breast pockets no sleeves, 2 breast pockets, locally tailored sleeve pockets, and then production sleeve pockets with Velcro patches. The ballistic eyewear also changed, etc etc.