Which leads to the fact that the calculations will have different end dates for the five participants (I'm including Centro, did Centro have the same start date?). It also made me think how much the statement, "The war is over, but they dying isn't" will apply to each of the five participants.I'm on the phone but I think in the battle of Nashville wiki box you made reference to how the casualties there were X% of overall casualties for each side of the entire war. You can always use that as a good starting point.
For the CSA, just because they've surrendered doesn't mean that the Winter of 1916 is have much more food available and the US will definitely be dealing with Insurgents.
For Mexico, the question that springs to mind is for a Mexican Soldier coming home from Georgia killed in Fighting in San Antonio, will they be treated as a GAW casualty. But I'm expecting that death rates in 1916 won't be significantly different than 1912.
For Centro, I think the Author has indicated that it may be decades before peace truly comes to Honduras & Guatemala, with them actually starting to look *more* like OTL. US Banana companies controlling the leadership with fighting in the rural areas.
For Brazil, the dying is over for now, I don't think the author has indicated how bloody the move to Integralism will be.
For Chile, we know the socialists end up in power, but how bloody the 3(?) way war is an open question.