Getting back to the OP... first lets review some core content of a excellent post. This is one way, & a good way, such a German strategy could work.
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von Rundstedt thought that this would mean the divisions would be attacking piecemeal, and would lack sufficient strength to push the Allies back into the sea; his preferred strategy was to concentrate the panzer divisions as a reserve, back from the landing beaches and in a central location until the whereabouts of the invasion could be determined, then he would attack with all of the panzer divisions together, an blow that the Allies would be unable to resist.
von Rundstedt then wanted to conduct a fighting withdraw, falling back to each major river line and making the Allies fight hard for the ground, essentially trading ground for time while husbanding his forces. Rommel for his part wanted to shorten his line, giving up the Cotentin and concentrating his forces in the critical ground behind Caen and there defeating the Allies in localised counterattacks as they tried to fight their way out towards Paris.
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von Rundstedt army had been allowed to conduct a fighting withdraw towards the Seine and beyond, then the initial Allied advance would have been faster, but the German army would not have collapsed in August, allowing the Allies to sprint forwards as far as their supply lines would allow them to, to the very border of Germany in a matter of five weeks.
The allies would have had to fight their way through northern France, which would have given the Germans time to demolish the channel ports (most critically Antwerp), and the troops stationed in the ports would not have been overrun and isolated; essentially lost to the defence of the Reich. The Allies may not have been approaching the Siegfried Line until December '44, and would have lost a lot more men in the process. With the major ports of Europe wrecked, the Allies would have then begun to really struggle to support the armies as they went beyond the Meuse and Moselle, stretching allied supply lines to the very limit.
This is also close to what the Allies expected the German strategy to be, and what they prepared to fight. The battle in the bocage country of Normandy was a suprise to them, and being stalled there for fifty plus days was not expected. Neither was the two weeks needed to capture Chebourg, nor the inability to execute Operation Chasity - the establshment of a third prefab port at Quberon Bay in mid July. the were some positive suprises for the Allies, but I'll get to those later. what is important at this point is the Allies were better prepared for figithng in the interior of France in June/July 19444 than for the actual battle in their Norman coastal enclave.
Now here area couple other good posts with some points that should be examined.
But they can't pull that off. Germany simply doesn't have the airpower or the tank divisions to place a force capable of crushing an Allied landing on every Northern French beach. Or rather they do but they're in Russia fighting for their lives. Rundstedt's strategy wasn't going to win the war for Germany but then no strategy could do that. However by trading space for time and making the allies pay for every French hamlet and river between Normandy and the Rhine they could inflict much more harm to the Allies at much less cost than their OTL strategy of holding on in Normandy until they Allies achieve a catastrophic (for Germany) breakthrough which see the Allies reach the Rhine in five weeks.
So, there the questions are: Can this strategy work vs Allied strength in the air, and in motorization? In June & July the Allies were able to average ten bomber or fighter sorties for each German combat aircraft sortie. Even at the peak of approx 1300 sorties per day the Germans had to confine most to night ops. Their losses by day were too large.
On the ground the Brits & US 12, 21, & 6th Army Groups came as close to 100% motorization as any Army in WWII. At its best in the west roughly half the German 'mobile' divisions had horse drawn artillery and internal supply transport. I dont have a count of divisions, or corps units for comparison at hand right now, but consider that with their attached tank and TD battalions the average US or Commonwealth infantry division had as many or more armored vehicles than most Panzer divisions of the summer of 1944. Also despite the presence of a few Panther and Tiger battalions the overall quality of the Allied armor was equivalent to the German.
Add in the ability to motorize their infantry at the operational level vs the German foot infantry & there is a clear disparity.
Or the Allies build up their Strength and achieve a Blitzkrieg in reverse with their much more mobile army's vs a more spread out German army rather than fighting a very intense battle of attrition that resulted in a relatively small battlefield.
Basically the allies get to choose where they fight
I dislike the word "bliztkrieg", and in any common usage it does not describe the British or US operational methods of 1944. Still at the tactical, and operational levels the last line in that quote sums it up. The Allies in the west have the ability to concentrate where the think best and to do so very rapidly.
Here are my remaining thoughts on this.
1. The Allies did expect to fight a mobile of fluid battle in the interior. Armies they had organized & trained in the UK were prepared for this as best they could anticipate.
2. The Allies did not expect to capture adaquate port facilities in the short run, and they knew from experience the German would demolish the ports. To counter that they had prepared the two Mulberry harbors and that for Quiberon Bay. Between those the Allies have enough port capacity to D+90 for the 12th & 21st AG. They also prepared salvage and construction units/material for restoring a couple of existing ports. That was a sucess. While the Germans destroyed the port of Cherbourg far more than the US Army or Navy expected they also repaired it far faster than the Germans expected. By mid August Chebourg was taking in 50% more than its nominal peace time capacity of 8,000 to 10,000 tons per day, and it hit a peak of over 20,000 per day a few weeks later.
3. The Allies had expected to restore the French railways in sync with the estimated advance. The stall in Normandy for fifty days prevent railway reconstruction out of Normandy, and backed up material and rail service units in the US and UK. The sudden surge across France left the rail restoration in a state or frantic catch up. That was not completed until about D+200 to 220, which is approx when they had anticipated. A series of delaying positions across France plays into the Allied capability, allowing the rail transport to keep pace. That resolves most of the Allied supply problems, unless the German delaying armies are destroyed and the Allied surge forward again.
4. Any sucess of the German delaying strategy depends on maximum motorized formations included. That also implies the better quality formations. Cherbourg fell swiftly because it was defended by poorly led second or third rate formations. Brest held out for many weeks because the timely reinforcement of a elite Para div bolstered it with decent leadership and top quality soldiers. Reinforcing the ports with such top tier units weakens and interior defense. The defender cant have it both ways, there are not enough top quality battalions. Or even medium quality. In any case by September the Allies had between the Cherbourg port group and the Marsailles group a intake of over 50,000 tons daily. It was not necessary to capture more ports in August/September. If the Quiberon Bay facility is operating then Antwerp becomes less important. Bottom line is the Allied supply problems were from transport, not ports.
5. Few to none of these internal defense strategies consider the effect of Operation Dragoon and the 6th AG pounding up from the south. Patch and Devers had perhaps the most sucessfull west Allied campaign in 1944, or from 1939 for that matter. In theory they could have been stalled with a adaquate defense of the Rhone river corridor. But, that requires a couple more corps, of good quality mobile units, & where are those to come from? Abandoning central Italy is the only option, and that assumes the Germans correctly anticipate a invasion of south France. Which they did not.
A lot more to this, but it will do for now.
