I think source of the confusion is the 1890 Veterans Schedule for Cole County, as the dates listed for those showing service in "1st USRC Inf" match service dates of the Cole County Home Guard, June 1861 to 1 Oct 1861.

There are the usual spelling variations but as one example the Schedule lists a John H. Trunnel, and the Service Cards for Cole Co Home Guard list a Henry Tranel, Pvt in Capt Lusk's Company B.

It may be that the census taker got confused. The card for Capt. William H. Lusk in 10th Cavalry list no dates, but the regiment was organized in Oct 1862, after the Cole Co Home Guard had been mustered out.