Another consideration here is the deployment of Soviet units.
On June 21 1941 these were deployed on mass on the front line, because Soviet doctrine determined that wars should be fought aggressively; they would attack the Germans before being attacked. This is why so much material was lost early on, particularly aircraft, which no sensible A&A player would ever leave on the front line.
This means that either the Red army will be grossly under represented, thus preventing the USSR player deploying defence in depth; or that the Germans will have a much harder time breaking through than they did historically.
Also, if the silly land movement rules remain the same it will take several turns to shift German units into attack formation on the eastern front after the French war, time in which the Soviets can build up considerable strength. My fear is that the Axis will have to use Japan to wear away at Russian strength in order to give Germany/Italy time to redeploy, whereas sensible rail movement would have avoided this problem.