@Lancasterlaw1175
I think your hypothesis is broadly correct.
But I think on a technical and logistical level (not sure about political), it seems to me that it was perfectly possible for the French to mobilize and brings the guns to the front much earlier, before September. This would’ve allowed them to begin attacking almost immediately and shatter the German lines. In retrospect, the French should be at fault for not mobilizing (and preventing the Poles from doing so).
The vast majority of Army Group C divisions were undersized (or even just command headquarters), while only about half of the French ones were deficient in some way (Nafziger’s book also lists the condition of French divisions in September-October 193o).
I got the book online here:
https://www.amazon.com/French-Order-Battle-World-1939-1945/dp/1585450189
