You already know about the record showing that Bruton later enrolled in Moreland's cavalry command. Many of Col. Moreland's companies organized in northeast Mississippi. Moreland himself had been Captain of the "Burnsville Blues" prior to returning to the area. He organized another company of cavalry in company with Capt. Warren. It's not uncommon to find men originally enrolled under Capt. Warren in one of Moreland's companies later in the war. For that matter, Phillip D. Roddey was orginally Captain of the "Tishomingo Rangers."
The 7th Alabama Cavalry served briefly in the Corinth area during 1864. It's possible that Bruton's name was misread somehow and wrongly associated with a burial from that command.