I think it's more about the fifteen minute frequency from York to Leeds than any particular demand from one east coast place to Manchester Airport - I don't think that it particularly matters which service has the stops at places like Marsden, just that one of the services needs to, and I guess it keeps things simpler to have all of the "fast" services running to York - otherwise I guess you'd need to have the Hull and Scarborough services at Leeds at the same time (if you were having four co-ordinated services from Manchester Victoria to Leeds and then four co-ordinated services from Leeds to York)
That said, I've suggested before that Scarborough and Middlesbrough would be fine with a good service as far as York with a reduced frequency west of there - it'd mean fewer of the short services each hour through Leeds - maybe that could mean a half hourly York - Scarborough and a half hourly York - Teesside (some to Middlesbrough/ Redcar, some to Sunderland when co-ordinated with the GC trains) but a significant reduction in longer distance trains
Except that in the current base WTT for York to Leeds as I recall you don't get 15 minute spacing anyway. The CrossCountry (and the Northern Blackpool pretty much) provide additional express services, so for anyone who is travelling "on spec" then there are still 5 or 6 services with a maximum of one stop to Leeds, and I am far from convinced there are many people travelling on a turn up and go basis from York to Manchester.
I think on the basis that there would be 3 TPE fasts plus CrossCountry, plus Northern's Blackpool, plus the Scarborough you could abandon the need to provide a particular clockface departure pattern from York. Instead provide the Hull and the 3 fasts as the Leeds to Manchester 15 minute clockface service. This idea that somehow York having an evenly spaced 4tph express service to Leeds/Manchester trumps Hull having
one express service per hour to Manchester (or even Liverpool!) is something I just can't understant.
I'd be inclined to rank the eastern origins on Transpennine in the following order:
Newcastle
Edinburgh (at this point York has 2tph which seems suitable)
Hull
Middlesbrough
Scarborough
I'd look favourably on anything that respects that kind of prioritisation.
Another point I find interesting is that the NPR project team have selected Leeds and Sheffield to Hull as the first phase they'd look to deliver. Now clearly that is partly about deliverability but lets face it, they wouldn't chose to prioritise something that they didn't think had a very good case in the first place.
That is what happens in the current Dec 2020 timetable, or did before the extra lockdown cuts.
In Option A the Northern Liverpool - Warrington - Airport service is retained, but the Cleethorpes train (or at least half of it) reverses out of the Piccadilly shed and runs to the Airport and back, as it did pre-Covid. The Task Force calls this reversing move "very operationally challenging", and gets rid of it in Options B and C by sending the Cleethorpes train on to Liverpool in place of the Northern Airport train.
I probably should have said 'whether it is deliverable in the context of the consultations objectives'. The idea I'd be thinking is that one (eg the Cleethorpes) terminates at Piccadilly, and the Liverpool-Airport express via Warrington Central is retained. Could that Castlefield path be repurposed for this and lined up with the CLC?
I'm not sure a second train per hour to Liverpool is of as much benefit to Sheffield as retaining a Liverpool to Manchester Airport service at all is, even given the 2tph timetable benefits.