From: Montreal, Quebec, Canada
I'll quote from Rommel to Field Marshal Keitel on June 12 1944
The enemy is strengthaning himself on land under cover of very strong aircraft formations ... Our own operations are rendered extraordinarily difficult and in part impossible to carry out [owing to] the exceptionally strong, and in some respects overwhelming, superiority of the enemy air force. The enemy has complete command of the air over the battle zone and up to 100 kilometres behind the front and cuts off by day almost all traffic on roads or by-ways or in open country. Manoeuvre by our troops on the field of battle in daylight is thus almost entirely prevented, while the enemy can operate freely ... Troops and staff have to hide by day in areas which afford some cover ... neither our flak nor the Luftwaffe seem capable of of putting a stop to this crippling and destructive operation of the enemy's aircraft. The troops protect themselves as well as they can, but ammunition is scarce and can be supplied only under the most difficult conditions.
Quoted in 'The Right of the Line' by John Terraine p.637
I think this quote reflects well that superior air power could disrupt and put chaos all over the rear areas, where troops are assembling to fight. It does not mean though that the Germans actually lost a lot of men and equipment because of air strikes. But air strikes spread chaos and hell and disrupt troops and tanks, forcing everybody to find some cover in all directions. In Normandy, the Germans could not use open roads and terrains freely during daylight. They had to move through woods or any covered terrain they could find, and this was severely slowing their operations.