Rommel commanded Army Group ”B”, which included the 7th and 15th Armies and LXXXVIII Corps, with three divisions for the defence of Holland. His main worry was the weakness of the defences on the beaches of the bay of the Seine, where three divisions were thinly stretched between Cabourg (exclusive) and the port of Cherbourg. More important, this weakness was not compensated for by the density or heavy calibre of the coastal artillery. Actually, on the 125-mile front between Le Havre and Cape Barfleur, the Swedish coastal artillery expert Colonel Stjernfelt has identified only 18 batteries, 12 of which could not reach the Calvados beaches or did not fire at all on D-Day.
Another concern of Rommel’s was what form he should give to this defensive battle for which he was responsible and which might begin any day. But on this question, his point of view was almost exactly the same as the Fiihrer’s, detailed previously.
In his opinion, a sea-borne landing differs from a ground attack essentially in that the latter has its maximum force on the first day of the offensive. It then decreases in momentum because of the losses that are suffered and logistic difficulties. This allows the defending army to put off its counter-attack. On the other hand, the enemy who comes from the sea will be weak at the moment of landing, but will become steadily stronger within his bridgehead, so that any delay at all in the counter-attack will reduce in like proportion its chance of success.
The Panzers were indubitably the best means of counter-attack, and so the sensible thing was to deploy them in such a manner that they could be hurled against the enemy wherever he might appear (Low Countries, Pas-de-Calais, Normandy, or Brittany) on the actual day of the landing. This is what Rommel explained in a letter to Jodi on April 23, 1944:
'Tf, in spite of the enemy’s air superiority, we succeed in getting a large part of our mobile force into action in the threatened coast defence sectors in the first few hours, I am convinced that the enemy attack on the coast will collapse completely on its first day.”
But he added: "My only real anxiety concerns the mobile forces. Contrary to what was decided at the conference on the 21st March, they have so far not been placed under my command. Some of them are dispersed over a large area inland, which means they will arrive too late to play any part in the battle for the coast. With the heavy enemy air superiority we can expect, any large-scale movement of motorised forces to the coast will be exposed to air attacks of tremendous weight and long duration.
But without rapid assistance from the armoured divisions and mobile units, our coast divisions will be hard put to it to counter attacks coming simultaneously from the sea and from airborne troops inland. Their land front is too thinly held for that. The dispositions of both combat and reserve forces should be such as to ensure that the minimum possible movement will be required to counter an attack at any of most likely points. . . and to ensure that the greater part of the enemy troops, sea and airborne, will be destroyed by our fire during their approach.”