I agree that they should leave. Some problems will arise out of that, though.
If the Austrians had had control of the Russians for quite a while, they may be a LONG ways from Russia, and could die trying to make it home. I think that the Austrians therefore need to remain in control in order to pay supply for them. But, they have to be moved as well. In this case, I think they should retreat as if they were Austrians for purposes of retreating (i.e. retreat towards the neares Austrian depot).
That could get REALLY hard to code. So, I would agree with a compromise that they should be repatriated, but to the nearest location in Russia, not to Moscow. And, the corps should remain intact.
One of the problems with repatriating as factors is that the corps was removed as part of the repatriation. But, what if they were guard factors? Now, the owner has no place to put them.
So, the corps counter that held them needs to be added back to the pool, as if they owner had paid for them normally.
At LAST! The greatest campaign board game of all time is finally available for the PC. Can my old heart stand the strain?