Would early helicopters replace glider assaults almost entirely?
Short answerFor infantry, probably yes; gliders may remain for heavy equipment, while assault helicopters require dedicated ships near the landing area.
NotesIn this scenario, helicopters would probably replace gliders for infantry insertion. Gliders could retain a role in carrying vehicles or other heavy loads. Practical range limits would require helicopters supporting the Normandy landings to operate from ships near the assault area. That requirement brings landing-platform-helicopter vessels into World War II. By Korea and Suez, helicopter assault could already be an established part of amphibious doctrine.