Richard, both Louis Gerteis (The Civil War in Missouri: A Military History) and Bruce Nichols (Guerrilla Warfare in Civil War Missouri, Volume 1, 1862) indicate that Confederate recruits, along with Quantrill's guerrillas, were involved in the attack on Independence August 11, however, they both also say that Cockrell with his recruits from Johnson County did not join the other recruiters until after the battle. If your ancestor joined with Cockrell on August 10, 1862, he was likely not at Independence on August 11 but may have been at the Battle of Lone Jack on August 16. Elsewhere, I see that the 10th Missouri Cavalry CSA was not organized until late 1863. Not sure what to make of that.

Tom Jones