Early German victories

We all know how the early German Blitzkrieg campaigns wiped out the enemy's armies in a matter of weeks... First Poland, then the Low Countries, France, and making England retreat back to the island while leaving all their heavy materiel. The Western Allies had more troops, better tanks and more numbers of tanks, but a lack of preparation, bad tactics, a defensive attitude, and not using their air forces in any affective matter killed their campaign and allowed the offensive minded Germans to sweep in and take them out in almost record time.

My question is, if Germany stormed into France but faced the Allies of around the time of D-Day (summer 1944), with the Americans, their massive materiel, air power, and troop numbers, and a planned joint-Allied effective strategy, would the Germans have had such an easy victory, if at all?

I think it could have turned halted the Germans and eventually push them back. There could have been a WWI-style stalemate for a little while, but eventually the Allies with their massive materiel and reserves advantage pushed them back and stopped the Blitzkrieg.

 

It's pretty obvious the 1944 allies would have won, in the winter of 1944 the Germans did try a repeat and the result was the Bulge.

But you don't need all the allied 1944 advantages to make the German 1940 attack fail, the French and British need very little more than what they already had to beat back the 1940 panzers. While they have nothing that can stand head to head with the 7 massed panzer divisions the Germans had committed to the main trust the Panzers are brittle and the German have no armoured reserves besides the remaining 3 divisions that are already committed in the North and would be hard to disengage against a more determined allied strategy. A serious setback to even one of the 3 Panzer Korps would probably stop the attack in it's tracks and they had ample forces to do that. The Germans needed all the advantages they had, the fighters the British held back, or few more experienced or aggressive leaders may have been enough to tilt the balance, better intelligence or 1944 armoured doctrine that made the DCR into self supporting units capable of sustained offensive operations would nearly surely have been enough.

 

The Allies had more armor and better quality armor in 1940 which is why they decided to turn the 88mm AAA gun on to tanks, they had more overall troops when you combined French, British, Belgian, and Poles that came over. They also were getting intelligence from Enigma that they didn't take seriously, not even to use it to prepare.

 

More and better quality armor as such means nothing .

 

IMO 1944 allies are much to strong for 1940 Germans. Here are some of my observations about 1940 allies chances if they had bit better luck, competence and will.

The original case yellow devised by the old guard generals in the OKH predicted similar route as in the WWI through the Low Countries into the northern France.Using one instead of two arcs later conceived.Fortunately for the Germans an unlikely event happened when Hellmuth Reinberger a major in fallschirmjager, lost his way in bad weather and landed in Holland.On him he had complete and approved plans for case yellow that were to be delivered to 2. Luftflotte Headquarters..the plans quickly found the way to the French.Capture of the plans convinced stupid French commanders that the attack was going to unfold exactly as they predicted,while the Germans of course immediately started to change their compromised planes.In the second planning a simple and brilliant plan devised by junior officer (by General Staff standards anyway) von Manstein was adopted.This plan decided the battle for France before it even begin..

But what if the weather was better that fatal day or good Hellmuth was a better pilot,anyhow if the plans reached 2. Luftflotte instead of the French?
The Germans would then swarm across the Low Countries on a relatively narrow front between the Ardennes and the see,just like the Allies expected,head on into the French First Army Group,the cream of their army+BEF.The real events showed that first army group did pretty good in front of German army group B,practically bringing their advance to a halt until Germans turned their right flank at Sedan and Dinant when they were ordered to retreat.But the original plan did not predict attack through the Ardennes and across the Meuse.Therefore they would be entangled in a frontal fight with tightly packed French units that were superior in number of tanks and artillery.
Now,what could the Allies do to perhaps even the odds somewhat,and I'll try to keep it within realistic parameters which could easily occur?If they achieved only three 'enhancements', things would look rather different.

-If French weren't satisfied,as they were,that over 60 of their divisions are looking from safety of impenetrable Maginot line to just 19 of Leeb's Heers Gruppe C,fifty or do French divisions could be redeployed to the critical,'live',sectors of the front.
-In accordance with their backward doctrines French High Command dispersed all of armored and mobile strategic reserves evenly across the front prior to the battle leaving only five infantry and one light armored division as a strategic reserve in whole northern France!French had 11 armored divisions,with another few being formed,plus a number of motorized formations.If at least half or two thirds of these units were held back to seal the cracks in the already strong line by determined counter attacks,Germans would have a though job.
-If British had been committed fully in air war over France(they contributed with just 100 engines) as they were fighting the battle for Britain,together they just might deny the Germans their complete air superiority,and deprive them of their greatest luxury..When things get rough(resistance get determined or counter attack hits the flanks) ,stukas fly in and problem is solved..

With these eventualities- no proper air superiority everywhere,going head on into massed Allied armies,German advance would be very slow and costly.And when a crack appears and elements of panzer division break through,they are met by superior numbers of counter attacking French tanks,with heavy Char B in lead(for which Germans had no answer except 88 mm flak,or to take them from behind). In this case Germans would bleed,with enormous casualties in man and equipment.Destroying First army group would probably take many months,giving even more time to Allies to mobilize their defensive potentials.Perhaps,Germans would still be victorious,but that shock effect that crashed French will to resist and pushed their leaders on collaboration path ,just wouldn't be.So even after defeat,perhaps French would withdrew to their colonies,with the army and fleet,strongly shifting the balance of power in Mediterranean,Atlantic and North Africa to Allied side and forcing already exhausted Wermacht to station massive reserves to guard the southern flank of 'Festung Europa'.Who knows how the war would then look..