whk4,
i prepare to stand corrected, but wouldn't the method you described above cause (in the chinook, for example), an inequality of lift between the two rotors?
i was under the impression that a pedal input in a twin rotor system caused differential cyclic inputs between the two discs, thus creating a yawing moment. e.g. for a left pedal application in the chinook, the front disc would tilt to the left and the rear would tilt to the right.
again, i am not too familiar with the mechanics of a twin rotor system and welcome any corrections to my impression of how it works...