Another thing that I feel gets left out with France in 1940 is how much they had deliberately nerfed their own army for political reasons between the World Wars. Mostly because France was in a politically unstable situation for pretty much the entire inter-war period, and many of their Leftist governments were more concerned about a coup by their own military than German aggression (as they felt their military officers were too conservative, monarchist, and Catholic). This is a large part of the reason they favored the Maginot Line, since a static defense cant march on Paris.

Hell, they almost got rid of all of their tanks (and some called for getting rid of the entire army itself) because some unknown general named Charles De Gaulle wrote a paper about doctrine for tank warfare calling for a professional instead of conscript army, and calling for dedicated armored divisions as the tank was such that it could set the pace of battle through shock and the power of the attack (as well as combined arms with air force units). He was crushed down on by army officials who told him they would absolutely not publish his paper, De Gaulle went and did it privately, and a French Socialist minister found his book and used it as proof that the French army clearly had ulterior motives to create an army loyal to French officers and sweep a new Napoleon into power by overthrowing the Socialist government.

What is more shocking is that the British were blindsided by this rather than the idea that the French army would collapse under such circumstances.