The Sunday timetable needs a good re-write, just like they did with the Mon-Sat timetable which gives a pretty much clockface timetable all day.
On Sundays the Buxton's interwork with the Chester's, which gives some trains limited turnaround times at Piccadilly. Also the Crewe line uses only 2 units on a Sunday, so turnarounds are very tight (only 4 minutes at Piccadilly) so calls at Levenshulme and Heaton Chapel just aren't possible.
If they re-did the timetable and diagramming for the Buxton and Chester services, I reckon you can easily get the Buxton's to serve both stations every hour, in both directions.
Perhaps you'd want one, or all, of the EMU-operated services to call, as it makes sense (to me) to have an electric service at an electric station. Also the Buxtons are slightly longer distance than some of the others, so should perhaps run fast - so to me a mix of the Crewe and Macclesfield (and Hazel Grove terminators, if they are still a thing - my experience in this area was almost exclusively in the 90s) would make sense. No idea whether that would work in practice.
Got no idea why they don't implement a clockface timetable going into Manchester, especially given Sunday shopping has been a thing for a while now. It would surely be easier to plan, for one thing.
4 min turnaround does seem unnecessarily tight, I suppose that's another symptom of the current DfT "thou shalt not spend money" dictat. What the Crewe line needs, of course, is an extra unit. I've always thought of 5 mins as the minimum turn around, but more like 8-10 in a large station such as Piccadilly.
