Another area of research that has never, to my understanding, been considered is the transition of mustered out soldiers in 1864 who returned home to Kansas. Many of whom almost immediately were mustered in to the Kansas State Militia and participated in the battle of Westport and the defense against Price's Raid in October 1864. Several soldiers of the 10th Kansas Infantry were members of Goss' Battalion of the Kansas State Militia and were killed in what was known as the Marmaton Massacre, a side action of Price's raid.
The true numbers of mortality of the men who originally joined from Kansas is clouded in numerous issues of miss-reporting, omissions, and, as you have pointed out, calculations in error. This would make an interesting project.