France forces where still considerable however in fact and still had more mechanised and armor divisions then the germans. however the germans did had the advantage in the air . France also had support from 300k man of the B.E.F. which where considered to be some of the best trained and equipped units at the time. What France lacked was that they didnt keep up with the new military doctrines. before 1940 they considered it impossible to attack france from the ardennes with panzer armies. they where wrong.
And why do you think they lacked these new military doctrines? They didnt want to go to war so they didnt put any effort into inventing. Germans on the other hand were preparing for war gathering expirience in Spain, and indoctrinating people in Germany.
Imagine this, if a #1 boxer is not training for 3 years, and a #5 boxer prepares himself during that time, who will win a fight? At the time of fight their rank is unchanged, but reality is different.
Before WWI both sides were preparing for war (arms race), that didnt go so well for Germans.