You see how fast those things swivelled?
Think about
: inertia of blades, precession, bearings required to fight such precession, hydraulic actuators needed to fight such precession, hydraulic pumps to move large amount of fluid in short swivelly time.
The shrouds around the blades were darned thick, would interfere somewhat with angled airflow.
But what the heck, it was a reasonable film.
