There is usually a twist throttle on the collective for a single engine helicopter. On twin engine helicopters, does the twist throttle control it for both engines, or just for one?
Most employ separate throttles, either twist-type, on the collective or levers in an overhead quadrant.
Bell products use duel collective mounted, twist type throttles, in series. Sikorsky uses overhead levers. French SA > AS > Eurocopter > Airbus > Leonardo use levers overhead. Agusta uses overhead levers.