Same thing with NY and MO, especially. In MO I have come across men who enlisted in 1861 in the Home Guard, then enlisted in the Enrolled Militia and/or the Provisional Enrolled Militia (often in both units at the same time), were "on detail" to another unit part of the time, and then mustered into Federal service. For NY, I've seen records of men who served in the State Militia, then in the Regular Army, then back to the militia, back to the army...each period of service 3 to 6 months for the army and 30 or so days for the militia. Kind of boosts the totals a bit. In my graves registration work , I estimate that every 5th man had two or more stints in service- either transferring from one unit to another, or simply multiple enlistments.

For what it's worth...