The fight at Upshaw's Farm on 29 October 1864 was actually a mismatch between the veteran Union 2nd Arkansas Cavalry and Confederate Colonel Eli Hodge's unnamed regiment of about 450 new southern recruits enlisted in Howard, Boone, and Audrain Counties, MO. As you indicated, the casualties were nearly all on the southern side, which is understandable since most of them were untrained and poorly armed or unarmed. This woebegone Rebel unit was pounded again for several days by different Union units until they could escape across the Arkansas line and later reached Confederate lines.

Sources:
--"Official Records," series 1, vol. 41, part 4, p. 403;
--Senator Emory Melton, "Civil War Days in Barry County," "White River Valley Historical Quarterly," vol. 5, no. 1, p. 11 (bare facts of the fight told from the Union perspective that failed to identify the Rebel combatants);
--James McGhee, "Guide to Missouri Confederate Units, 1861-1865," pp. 115-7 (a detailed summary of Hodge's regiment and what happened to it);
--Eakin and Hale, "Branded As Rebels," 209, 252 (incomplete information about Hodge);
--"Col. Eli Hodge (obituary)," "Confederate Veteran," vol. 33, no. 5 (May 1925), p. 186 (a valuable southern source for Hodge's regiment and its travels and travails);
--Frederick Dyer, "A Compendium of the War of the Rebellion," vol. 2 of 3, p. 813 (bare bones facts about the Union side of the 29 October fight);
--State of Missouri, Secretary of State's Office, Missouri State Archives, online military service record of Colonel Eli Hodge giving details of his service as adjutant in the Confederate 6th Cavalry Regiment, a record of battles in which he participated, and a rather complete record of his recruitment of the subject regiment and its tragic trip south to join the Rebel army in Texas, taken mostly from the "Confederate Veteran" obituary of Hodge.

Jack, if you locate any other sources about this action, please pass their citations along to me.

Bruce Nichols