Why early helicopters cannot simply be made shorter

Could early helicopters be made shorter as their designs advanced?

Lower aircraft are possible, but early radial-engine layouts tend to increase height as power rises; historically, taller carrier hangars already built for jets eased the fit.

Radial-engine layouts drive much of the height of early helicopters. More powerful radial engines can make the aircraft taller as designs develop. Historically, capable naval helicopters arrived when carrier hangars had already grown to accommodate larger jet aircraft and their maintenance needs. Moving those helicopters into the 1930s brings the hangar-height problem forward.