The French army didn't reach the Siegfried line
as said on the wiki.
Well, the only way I see this going, is somebody other than Gamelin at the top.
A halfhearted 11 division advance into undefended territory.
well, if more is attempted, it's likely that 'Sitzkreig' never gets coined, if you can get some French General to try what Patton later planned, send 5 Divisions of the 3rd Army towards Saarbrücken, with aims to get thru the WestWall fortifications, but without the part of having to redirect them due to the 'Bulge'.