Mr Lewis's extensive research is narrowly, and wisely, focused specifically on the planning for the Omaha Beach landing. His thesis is, there were two diametrically opposed amphibious operations philosophies. The first, espoused by British commanders, was a night attack with minimal gunfire support, thus maximizing surprise. The British with minimal resources, needed to exploit surprise. The US ideal was, maximum gunfire and air support with a large landing force to ensure a beachhead; American forces having more resources at their disposal. Finally, a excessive faith in what aerial attack could achieve almost spelled disaster on Omaha.
The Overlord landings in general, were a compromise of both these methods. A landing at first light, and with minimal naval gunfire support-to maximize surprise; but with mass and an aerial bombardment to overwhelm the defenses. As history demonstrated, this was almost a recipe for disaster. The "Soldier's General" (a newspaper attribution, he was never considered that by this troops) Bradley comes off badly here. Overall, a detailed study of how coalition planning can fail and a useful tonic to the "Greatest Generation" media. Highly Recommended.