Qvist wrote:
3. It is however in my opinion undeniably the case that Rommel's arguments against this approach were essentially correct, as borne out by events. What is notable is furthermore that it was put forward by a general that was hardly in any way a proponent of static warfare as a matter of doctrinal preference or principle, and that it was put forward well before the invasion took place. This is significant in my opinion because it demonstrates that it was possible to foresee the factors that rendered mobile defense an irrelevant option.
5. One point where I do disagree with you is that both approaches were attempted and that both failed. Rather, I would say that neither was attempted.
As for the notion of maintaining a strong Panzer Reserve for a decisive counterstroke, it was made irrelevant within days of the invasion through the simply neccessity for committing the immediately available Panzer formations to the line as soon as possible, and then by the gradual absorption of the remainder as the defending forces were gradually whittled down. Rundstedt’s intended strategy was never put into action, because there was never any possibility for it to be put into action. As such, we do know that it did not work, or rather that it was irrelevant, infeasible. Rather, OB West was compelled into a policy of releasing Panzer divisions piecemeal while attempting to preserve some reserves. This ensured that the German forces were not left without coverage in other sectors and conserved forces that could be used to bolster the line at requisite points in time; as long as the allies were winning the build-up race, it also made complete defeat simply a matter of time.
Concerning the approach favored by Rommel, that was hardly attempted either – for the first 36 hours or so, there was only one Panzer Division in action against the invading forces, insufficient to even deal adequately with local challenges. Possibly you are thinking of the inconclusive results achieved by 21st and 12th SS PzDs in their early counteroffensive operations, but here I would say that these reveal lost opportunities as well as inherent limitations, and that it could just as easily be argued . 21st PzD managed to find an open right flank for the forces advancing on Caen from Sword – but could not exploit it due to its own wide open left flank against the forces advancing from Juno. Obviously, with a Panzer Division operating on its left flank it would not have been. This is not say that in such a case 21st PzD can reasonably be xepected to have overrun Sword beach, but it is to say that there existed possibilities that could not be taken advantage of due to the absence of forces. When the first elements of 12th SS PzD went into action, they inflicted a serious setback on the Canadian spearheads advancing on Caen, after which the Canadians, having achieved after all a sufficient immediate defensive depth for their bridgehead, went over to a defensive stance and in turn inflicted a firm rebuff on Meyer the following night. What this seems to indicate to me is that there existed opportunities and scope for German offensive action during the first two days or so, while the allied forces were engaged in landing, securing their beachheads, establishing contact between them and advancing not only to secure important objectives, but also to gain a minimum of defensive depth. It does not appear that allied air forces or naval artillery essentially eliminated German freedom of action at this point. And in any case, the drawbacks of operating within range of naval guns is something of a self-defeating argument, given that the only way to avoid it would be to withdraw beyond their range – which would essentially amount to conceding inevitable defeat.
6.There is one – and only one – precondition why anyone would contemplate Rommel’s approch, and that is acceptance of the judgment that to the extent it was possible to defeat the invasion at all, it only existed during the first 48 hrs or so. If you accept that: Certainly, there were not enough forces to implement Rommel’s approach – at least not throughout the OB West area. But there was always the option of simply accepting the risk inherent in concentrating the mobile forces in the most likely landing areas (Calais, Normandy). If the guess was wrong, well, then any chance for a speedy defeat of the landings are gone. But firstly, the allies have then at least landed in Brittany, Southwest France or the Mediterranean, rather than in the immediately more dangerous sectors. Secondly, your position for reinforcing the invasion front is not fundamentally worse than it would be if most of the Panzer forces were scattered around France. And thirdly, if you concentrate them nowhere, then you have zero possibility wherever they land.
Also, if you accept that, then a logical implication of this would be local control of forces without OKW/OB West consent in each case, and also a general emphasis on speedy reaction. Whether this implication would have resulted in a significantly different command arrangement on the German side is a different matter, but it is at least possible.
7. Let us return to the events as they did unfold. One thing is the argument of which approach gave the better opportunities in terms of campaign outcome, another is which provided the better situation relative to the actual situation the Germans found themselves in – which was that their forces along most of the invasion front, and certainly in the British sector, were within a short time pushed beyond any capability of maintaining even a tenuous defensive line, which neccessitated speedy commitment of mechanised formations – in all, it required the commitment of three Panzer Divisions in the British sector and a Panzergrenadier division in the US sector before the situation can be said to have been relatively stabilised. The emphasis then was in any case on swift intervention – and it does appear to me that a concentration in the Normandy and Calais sectors would have facilitated this more than the course chosen did.
A very intellingent comment on Rommel's approach which was the correct one.
Effectively the coastal defenses were too weak and an averagely strong defense of the threathened coastal sectors could only be achieved by using the operational reserves and a strong operational reserve would mean taking troops from the coastal defenses(Rommel,Krieg ohne Hass p382).
Weak coastal defenses combined with enemy air superiority meant that before the operational reserve could arrive the enemy would have landed a force of such a size that the operational reserve could not pUsh it back into the sea anymore.
Even in Rommel's concept panzer and motorised units from other sectors would move laterally along the coast while those in the landing area helped in preventing the enemy from enlarging his bridghead to the size needed for the support of large units(Rommel Krieg ohne Hass p.384).On the possibility of lateral moves a quote with the opinion of General von Salmuth:
" For Armee Oberkommando 15 ,Generaloberst von Salmuth the basic principle to operate with strong reserve units from the depth was not of central importance particularly because the density of the road network of Belgium and France just as well allowed a lateral movement of big units. Anyway the greatest danger that threathened the fast units was the superior enemy airforce, which could cover movements from depth or from the side in a coastal sector which was under attack"(Die Abwehr der Invasion,Wegmüller p.135).
The advantage of Rommel's concept lay in the fact that the presence of panzer units immediately behind the landing area could enable the coastal defenses to keep the enemy bridghead small until the arrival of panzer and motorised units from other sectors to prepare for counterattack.
If the landing did not occur between Brittany and the Netherlands, it would not make a significant and decisive difference when moving them towards the landing area that they had to come from relatively near the coastal areas between Brittany and the Netherlands. If a landing unexpectedly occurred in the south or southwest the extreme weakness of the defenses there would make it impossibly anyway to push the allies back into the sea.Giving up a large part of France would then be inevitable.
Given the resources available being strong everywhere was not possible and so a risk had to be taken. There was therefore a very good case for having almost all panzer and motorised divisions relatively close behind the coasts btween Brittanny and the Nehterlands.
It is effectively significant that Rommel who was not a proponent of static defense would defend such a concept.This had everything to do with drawing from practical experience the necessary conclusions from the effects of allied air superiority on the german ability to conduct mobile operations.
And much of the garrisoning decisions in France - as in other countries - appeared to revolve around availability of former French Army facilities and training grounds, at least for the "mobile" reserves. 
