This is a common problem we have with men in any state. Not everyone served, no matter what anyone may tell you.

The Confederate government elected not to enforce conscription in certain parts of the state. In many areas, such as that part of the state west of the Tennessee River and the Cumberland River valley near Nashville, conscription could not be enforced. That's because the Federal military controlled those areas from February-March 1862.

Just my guess, but I'd suppose at least a third of the men ages 18-40 living in Davidson County didn't enroll during the war.