In a default MH-6 or AH-6 pull about 80% Torque, lower the nose and let the aircraft accelerate. Let the airspeed stabilize and once it does roll the aircraft to the right or left and start pulling aft cyclic to tighten the turn. You notice you can hear the NR start to droop and if you persist you'll lose enough NR that the low Rotor RPM horn goes off and the aircraft begins to wallow. This is in fact the opposite of what should happen. Upon entering a high G turn in a helicopter the NR will if anything start to climb as the force of the tightening turn will cause the RPM to increase. In a real helicopter one way to recover rotor RPM is to lower collective and either flare the aircraft slightly or enter a high g turn which will increase rotor RPM. In addition if the throttle is rolled off and the rotor is free wheeling you actually may have to add some collective to keep the rotor from overspeeding. However in Arma 3 the opposite occurs and even if you lower collective fully before rolling the aircraft and pulling aft cyclic the RPM still droops which is incorrect and should really be addressed.
In addition if you lower collective sharply in the Mohawk the NR overspeeds and if you raise it sharply it often droops. The aircraft simply doesn't react like this fortunately with a few tweaks to the blade inertia I expect this too can be corrected.