Idea:
I have a little idea that might do this NES more realistic.
I think you can add "Winter Technology" , this technology shall have under gruops like the "alpine" tech, but also a tech that shall make infantery better at winter (like winter cloathing and winter tents) and for ships (Ice-Breaker) also something for tanks (like winter wheels or something).
Some nations (the northern ones) can get a bonus in reachershing them, this would acctualy make an Finish-USSR war more draw than it is....
Also it shall be "Desert technolongies" that have things like "jeeps" (better infantery in desert) and such....
I hope you like the ideas....