Playing birds of a feather flock together...Also in Co A Shanks Regt. is a gentleman named Milton Wilson a bit younger than Granville Wilson. Milton is also from Everett, Cass County, MO. I've not found a direct relation link between Milton and Granville yet but suspect they are 1st or 2nd cousins. Age, nativity of family (Virginia), appearance in Cass County all seem to point that direction. Circumstantial evidence at this point that 6th MO Inf guy is same as 12th MO Cav.
Granville W Wilson of Clark county fought in Mexican War but was born 1806 and died 1863 so scratch him off the list.
John R