I would order a fly plaid in the Army Tartan also....but to RCallan;
As a soldier with 24 years of service I say you don't have to have served to wear the Army Tartan (it is a universal tartan) Wearing the Army Plaid just shows all that you support America's Warriors and that goes for the USMC (Leatherneck Tartan as well),USN,USCG,and USAF Tartan as well. So If you like it wear it! Show your support.