When deploying Watchman Monitoring to a number of computers at a time, best practice is to install the Monitoring Client via a post-restore action. This ensures the installation timestamp is accurate, and the Client ID for the computer is unique.
If the client is installed, then copied into a master image, a single Client ID would be restored to every computer imaged from that master. Since multiple computers would report with the same Client ID, numerous "Something has changed" emails would occur.
If this occurs simply mark the Client ID for reset on the sever and hide its client record. Every computer with that Client ID will see the Rekey flag the next time it checks in and automatically generate a new Client ID.