Overlord answered coastal defence with engineering and massed firepower

Hobart's Funnies mattered because scarce engineering vehicles cleared mines and obstacles for ordinary armour; their rarity also made them priority targets. Percy Hobart did not invent every vehicle, but he sponsored, selected, developed, and trained the ideas into a usable formation. Thousands of landing craft and hundreds of minesweepers supported the assault, while land-based aircraft made carriers unnecessary and avoided expanding the swept sea room they would require. Battleships and destroyers supplied crushing fire support against German armour. Overlord's preparation contrasts sharply with Sea Lion and shows how the strongest Pas-de-Calais defences shaped the Allied choice of Normandy.