Yes, with a name like Charles Hall, there could have been hundreds with the same name who served in Vietnam.
In his first book, Charles Hall claims he reported to Bihn Thuy as "Airman Second Class "Charles Baker"
"As I stood watching, an Air Force master sergeant in his early 30’s got out from a dark blue USAF van parked nearby. He greeted me as he approached, “I’m Master Sergeant Walters. You’re
Airman Charles Baker, aren’t you?” “Yes,” I responded. “
I’m Airman 2nd Class Charles Baker, reporting for duty.” “Place your duffel bag in the van, and we’ll get started,” he responded. “We have a mighty long drive down to the southwest to get to the Desert Center Air Base. It’s several hundred miles. We’ll have to make good time if we intend to arrive before the chow hall closes.”
Hall, Charles James. Millennial Hospitality (pp. 8-9). AuthorHouse. Kindle Edition.