I don't believe Clanton's command was engaged at with Rousseau at Chehaw Station or later. Also, only the 6th Alabama Cavalry served with the Army of Tennessee in Georgia, and then only from late May to end of June 1864. See notes on the AoT order of battle for June and July 1864. The War Department asked why this regiment disappeared from the army's register. General Johnston's response is quite enlightening.
Capt. C. T. Hardman's letters are available in bound form in the Southern Collection-BPL. I have a strong recollection of one he wrote from Blue Mountain during the time that fighting took place at Resaca GA. Do you have contary evidence?