Who's Who in the Military...at Area 51
Just to confuse the issue inj a typical military manner....
You lot are regular Army attached to the Air Force. Area 51 is an Air Force base, after all.
Recently (since the invasion) members of the new branch, the Space Force, have moved in and taken command of aspects of Area 51. Not particularly strange as they ARE a subdivision of the Department of the Air Force. Much like the Marines are Department of the Navy.
It should be noted that the remit of Space Force includes responding to attacks and issues from Space.
Impact Site 51-A is manned by Army, mostly Special Forces and Snipers, but it, too, seems to be run by Space Force. While the soldiers aren't form Groom Lake or the Air base at Area 51, the Space Force contingent probably is.