Part of a reply from Merseyrail in answer to my complaint about ovecrowding & delays at Sandhills. No mention of insufficient number of trains and carriages. They seem quite happy with how things went.

<<<< The purpose of test events, like the one held in February, is to identify improvements and adjustments that can be made to ensure matchdays and large events progress smoothly and safely, particularly in terms of crowd management and managing the flow of passengers onto platforms. These test events will be subject to a comprehensive review with all organisations and partners involved, with feedback provided to LCRCA.
I’d like to reassure you that the queuing system at Sandhills station is based on the tried-and-tested arrangements used for major events such as the Grand National at Aintree. The number of people allowed onto platforms from the queuing area is carefully controlled and in line with risk assessments carried out for the safety of our customers. >>>>