To answer your question, a number of men escaped service by having a substitute enrolled in their place. Often the man in question procured a substitute after enlisting, and the substitute took his place in the same company. That can't be true in the case of Goldsby's Company, which didn't exist until the 2nd half of 1863. It was largely composed of exempts who enrolled for local defense.

Mr. Baker and others like him soon had their exemptions revoked by Congress and were obliged to enroll. Goldsby's Company then went to the eastern shore of Mobile Bay where it was involved in a least one skirmish. Perhaps Mr. Baker learned that the company was leaving for the coast and got a job with one of the many arms manufacturers in Selma to secure another exemption.