Here is how to fix France 1949 going through Russia with one days worth of work.

[Schmidty]

Instead of working on this and failing for multiple years, just block off Lake Ladoga, Volga River, and The Great Lakes and you fixed the entire problem of AI getting stuck in Russia and The Great Lakes. You could do this in an hour probably instead of utterly failing for multiple years to fix this. Warships are not needed on those rivers and lakes anyway, you can't go continously from Lake Ladoga to the end of the Volga by river either, would have to get off at Vitebisk to cross the 2 river networks. Please fix, about time already.