I agree...no way of knowing for sure. Same for Union totals. There really is no way of knowing the actual numbers that served. What with transfers, reenlistments, men joining for the bounty/bonus then deserting and doing that several times, name changes, etc, there is no way of knowing for sure. In my graves registration, I've found that about one in 5 (20%) served in more than one unit, especially if they were from states that had their own units (like MO).