A consistency group is defined to include a set of required devices on a set of storage systems. High activity devices are determined, and write dependencies between each high activity device and each low activity devices are monitored. A set of high importance devices is determined to include the high activity devices and low activity devices with a high write dependency on at least one of the high activity devices. Comparative write patterns between the high importance devices and low importance devices are used to determine a set of candidate devices for removal from the consistency group. The high importance devices, rather than all devices of the consistency group, are also used to determine a set of devices that have inadvertently not been included in the consistency group.