The German army helmet was a superior design back in the late 30s and was shown to deflect more shell fragments, and its shape could also deflect some bullets at long range.
It also had far better prtection for the shoulders and neck due to the flares on the lower portion and the front rim was designed to keep rain out of your face..
This is pretty much the standard design today except in airborne divisions world wide with a few modifications here and there.
You asked.
