If earlier scans exist with work to do then Discovery will not start later scans. In consolidation there are less IPs scanned at the same time. This is because the consolidator does not have to wait for discovery results. On a scanner while waiting for a discovery result it can do work on other IPs.
I don't know what you mean by "cancelling the consolidation scanning". If you can the scan on the scanner it will still consolidate the work done on the scanner to the consolidator.