Moin,
I´m certainly not the authority on this subject, but this is what i reckon. The models of the crew just rotate to give the impression of a real scanning process. The state machine system indicates that they will spot a target regardless of direction of view as long as it is present in their sector. There is an entry named 'RotateToTarget'. Whenever a target enters the detection range / range of view the respective watch will report it and turn to it´s direction immediately. So, you´ll never know he reported the target before actually looking into the right direction. The watch officer is indeed a more powerful sensor, but the reason for that is obvious in 'WatchMan' node. While the sectors of each watch crew covers 90° only, the watch officer has a full 360° view. As a conclusion it does not matter whether any of your watch crew is standing still transfixed to the spot or not. He will spot the target anyway when close enough.
That´s my two EuroCents. I´m not sure I´m right. So, please, don´t nail me down on that.
Regards,
DD