I now think a similar idea could apply to Finland.
Its 4 infantry can only move in the following territories:
Finland
Vyborg
Karelia
Norway
Sweden (not if the Axis are at war with the strict neutrals)
USSR: 42 (Russia worth 8, Caucasus and Vologda worth 6, Karelia and Novosibirsk worth 4, Archangel and Kazakh worth 3, Okrug, Yakut, Far East, and Buryatia worth 2
Germany: 40
UK: 24 (UK and India worth 6, Egypt and Australia worth 2, South Africa, Trans-Jordan, Western and Eastern Canada, Burma, New Zealand, Gibraltar, and Persia worth 1
Japan: 30
USA: 30 (Eastern and Western USA are worth 10, Central worth 6, Mexico and Panama worth 2)
Allows the USSR to hammer Germany and Japan. USA and UK are weaker to represent slower mobilization times. Also forces Allies to ensure USSR survives, or perish.