I have always been fascinated by the original plan.
The German generals nearly had kittens when they got that plan presented.
It was totally impossible for many reasons:
1) German army not ready after Poland. a lot of things had to be re-supplied and strategy ironed out
2) Weather: Northern Europe in November is not exactly the best of times to invade anything
3) More weather: 1939 was COLD
4) Schlieffen plan was the only realistic plan in 1939.
5) Ardennes (If Manstein even would have thought of it) was totally impassable in winter and especially in 1939 November
So, not much going for it, BUT
On the "pro" side
1) BEF not in place.
2) Totally un-expected, so surpise is surely on the side of Germany
3) It has to be invasion of France as well, not just Belgium and Holland
However, it is not the best plan in this world.
If the conflict really will be between France and Germany (BEF can be ignored to some extent in November 1939) then it is more a matter of strategy and tactics and blitzkrieg" rather than slogging match.
How will France hold up in 1939? Will Germany have the chance to do Schlieffen at all? even in 1939. German army was not particular mechanised, it was "foot and hooves".
Would Germany have had to do something about the Maginot-line in this scenario? good guess. The forts around Paris?
Ivan