Just some thoughts on France and the UK. By Spring 1940 France has almost the same IC as Germany (whereas in reality the French economy was only a little over half the size of the German) French GDP in 1938, last full year of peace=~$186 billion, German=~$351 billion). This makes allows the French AI to create a very large, and highly modern military force. And although the French Military was larger than the Wehrmacht in 1940, only a small part of it was actually equipped in a "modern" fashion. I think a better way to represent the French Military would be to have most of the Army be made of Model 1926 or 1931 infantry divisions, with a smaller core of 1936 and 1939 (around 45% of the Force) infantry divisions which the AI should deploy in the Amiens, Hirson, Dunkerque, Calais provinces, with the older divisions mostly concentrated into the Maginot lines and screening forces deployed in the Ardennes. This follows the outline of the French Deployments at the start of the German Offensive. In addition to this problem the French AI is extremely aggressive, launching frequent assaults into the Rhineland, and Freiburg. The French AI also leaves no troops in its colonies, or on the Italian Border and concentrates nearly 40 divisions in the Ardennes region thus making the German Offensive (from a historical perspective) impossible. In addition their air force is hyper active, it attempts to assert air supremacy over Germany. They didn't call it the "Phoney War" for nothing.
In addition to problems with France, the UK has almost 60 infantry divisions stationed in Southern England, which they just flood into Belgium instantaneously once I invade. If I can recall correctly the BEF was never more than 12 divisions (with around 315k troops) not over a million men in Flanders within 3 days of the German Invasion. And although the British Army did posses a little over of 1,000,000 men in 1940, this does not directly translate to combat ready troops capable of being sent to France/Low Countries. Large numbers were still relatively untrained, thus not greatly adding to the combat power of the Allies.
Difficulty and AI Aggression are on Normal/Normal
After re-simulating the game several times I continue to achieve these same results.