Saunders DID have a first name. It was "Chip", typically a nick for Richard although I don't believe that was ever clarified. And it was stated right from the beginning of the series.
As prisoners are signing the roster, a German reads each name aloud. Apparently, Saunders just signs "Sgt. Saunders," since that's what the German says. This is in keeping with the running storyline that Saunders has no first name.
Not sure why someone thinks Chip is a "nick" for Richard, but in general, Chip is a nickname for the name Charles. Saunders doesn't seem like a Charles, much less a "Chip," but since that name is used in at least one or two instances in the series, it's likely Saunders' first name is Charles.
The show's plot would have resulted in Sgt. Saunders, Kirby, Caje, Nelson, Little John, Doc, Sgt. Akers, and Gates being awarded the Prisoner of War Medal. Saunders would have also received a Purple Heart for his burns.