One possible explanation is that there was two Montgomery guards and maybe three.

Captain Guilmartin's company, Chatham County 1ST (Olmstead's) Regiment Georgia Infantry which later became Company E, 22ND Battalion Georgia Heavy Artillery.

Then company K, Richmond County 20th Georgia Infantry.

and Company A, Meriwether County 2ND Regiment Georgia Cavalry, State Guards. Company A was also known as "Meriwether Volunteers" and "Empire State Defenders".