Exactly. Linking back to the Bolton-Scotland issue, I’d base it all on the question of what is Bolton station for? I see it as simply a funnel for Manchester services, of which 1 tph should certainly be an intercity service to Scotland, with the rest connecting to Manchester with a combination of fast and stopping services. Minimum 6-car commuter trains. I can’t ever see TPE extending the 397 units, so if additional capacity was to be ordered for that route, it would likely come in the form of a new order of trains and the current 397 fleet used to bolster Liverpool-Scotland.
The railway is effectively a Bolton-Manchester tube line, that being the overwhelming demand at Bolton.
Scotland services do generate some demand at Bolton, but the service provision has been erratic over the years in a way that, say, somewhere like Stockport doesn't suffer from, with:
-Pre-2002, a handful of Scotland trains per day, I think up to about 5 or so at the peak
-September 2002 to May 2003: Every 2 hours under 'Operation Princess'
-May 2003 to December 2004: Cut back to 2 stops per day each way in the recovery from Operation Princess:
-Dec 2004 to Dec 2007: Every 2 hours restored, but with services largely split at Manchester (except 1 per day running through south of Manchester to Stafford / Birmingham)
-Dec 2007 to Dec 2013: Every 2 hours operated by TPE, increasing to pretty much full hourly service
-Dec 2013 to May 2018: Trains diverted via Chat Moss with Bolton stops withdrawn
-May 2018 onwards: Trains restored via Bolton with some limited calls introduced
So service provision has hardly been consistent over the last 20 years!