Could've have been a couple of reasons.
Many people misunderstood the new law placing men in the age range 45-50 in Confederate service as senior reserves. I've already mentioned the mistake of including junior reserves (age seventeen) on roll with senior reserves when companies assembled in May 1864. Perhaps WGC wasn't sure about the upper age limit: was he liable for service up to age 50 or not? He might have preferred local service as opposed to joining the Confederate military. Evidently many felt that way.
Duties of Larkin Breed's 1st Class Militia included enforcement of Confederate draft laws, so in effect WGC became a county deputy.