Sept 17-24
During the last week the French succeeded in clearing the Siegfried Line south of Karlsruhe, but the Germans have done an excellent job of positioning their troops for a slow withdrawal to the east, not allowing the Allies to breakout. There is no rail movement for the Allies beyond the border, so bringing up the newly mobilized French and newly disembarked BEF has been slow also.
Recon shows that the German maintained their force along the Siegfried line northwards towards Belgian, not pulling out forces to move south against the Allied offensive.
With only a few days left in this planned offensive, prior to repositioning for the expected assault of German forces coming from Poland, it is looking doubtful that the Allies will take either Karlsruhe or Stuttgart.
Therefore the entire offensive has been nothing more than a nuisance, albeit a bloody one, for the enemy. To make it worse, the French air force has been worn down to parity with the German air units on the Western front, and when the arrival of reinforcements from the East, Germany will have total air superiority.
Even worse, the Dyle Plan is now completely out of the question, with the BEF fully engaged in the south.
The French regimental armored units do not have any punch and are incapable of forcing a breakthrough.
It's clear from this scenario, if the abstracted elements of the game system do justice to history, that such a French offensive would not have altered the course of 1940 action on the Western Front all that much, and may have actually weakened the Allied defense. Certainly the BEF would not have been rescued if it had been committed to the Saar.