A few thoughts on Sandhills . Believe it or not there are currently 10 trains an hour from Sandhills into town because 3 different services run through from Southport ,Kirkby and Ormskirk . So the maximum wait on the platform would be little more than 5 minutes .I can't see much scope for an increase in that frequency . If you're going into town it might not make sense to walk to Sandhills and then queue . Going North also 10 trains an hour split between the 3 destinations.At the moment, transportation appears to be reliant on people walking to the ground, utilising Sandhills (concerns about this), shuttle buses and parking.
So ,in my opinion ,no problem with trains frequency as such but getting onto Sandhills station post-match will require split queues as there is only the one entrance for both directions . Crowd corralling seemed to work well at Wembley Park last time we were there so I expect to see something similar. No news from Merseyrail yet though.