[The Dark]

I can see both sides of the argument. On the pro-desertion side, when these guys hear things are going to hell in a handbasket, a lot of them are going to want to get back to their families, similar to how the rate of desertion of Georgian troops in the US Civil War spiked during and after Sherman's siege of Atlanta. In the Appalachians, there were instances of deserters from the Confederate Army forming their own units that fought off Confederate regulars. A historical study of the deserters found there were two common factors that led to desertion: hardship among their families and finding out their home district wasn't united in support of the effort. With the MilGov/CivGov split (and New America), there's likely to be wavering support in many districts, and severe hardship among soldiers' families, which will cause desertion higher than usual. I don't know if it would reach 80-90%, but given that the Soviet Border Troops had 60-80% desertion rates during the Afghanistan War, it's likely it would be much higher than most people would suspect.