1. Bridges, or namely, blowing them up: it might be better, if not all the units had the capability to destroy bridges. Currently a cavalry squad with a machine gun can easily destroy bridges on super rivers, which requires a truckload of carefully placed explosives.
2. Rivers - there might be some intermediate type of river, in the middle between a river and a super river.
3. Railroads - Russia/USSR has a different gauge of railroads; if two different types of railroad gauge were added, it might help all the designers of Barbarossa/WW I scenarios.
Just a few thoughts...

