Robby --
Thanks for your reply. Each of these men must have had an exemption. Rolls often clearly state them for the sake of Confederate authorities wanting to know why these men weren't in regular service. Revision of the military laws at the end of 1863 and early in 1864 removed most exemptions that had kept men out of service.
It would be interesting to know the nature of Sgt. Malcom's exemption, as it must have survived Congressional action during the winter of 1863-64.