Snake Featherston
Banned
To me, moving a unit or two to block the Germans in the Ardennes is nice, but not a show-stopper IMO. Some sappers that could mine and block roads would be nice, but so would artillery, and maybe better CAS from Armee de'l Aire to call the Wehrmacht's bluff.
I hear y'all bringing up Weygand as a better overall French theater commander and De Gaulle as having a tactical clue to go with their better ability to resist but IMO, the French Army's problem was that combined-arms doctrine, tactical and strategic coordination, mobile defense-in-depth thus and ability to counter-attack) was for merde b/c of piss-poor preparation for the Ardennes attack.
As mentioned before, they were prepared for Von Schlieffen Plan part II through the Low Countries.
The French had courage and ability to improvise under pressure and plenty of gear, but no good plan everyone got and executed until it was too late.
They were prepared for that because they captured the initial German plan that indicated that this is what the Germans wanted to do (and as it was Germany's generals certainly did want to do exactly that). Butterfly this away and they've more reason to at least initially use superior firepower and mobility to devastating effect on the Wehrmacht.