I think part of the problem is the bunfight to get anything out of KGX in the evening peak (which is the harder one to plan as the long-distance peak coincides with the commuter one). In an ideal world, I think EC would have preferred to run the 1835 KGX - LDS a few minutes later, but there's the small problem of the 1840 and 1844 FCC fast commuter services (non-stop to Biggleswade/Royston respectively) running just behind (and noting that anything that FCC has will accelerate a damn sight better than anything EC runs)
So I suspect that the path that is provided is the best of a balancing act:
- Use the fast lines KGX - Biggleswade when they are available
- Try to balance the calls at Stevenage, Peterborough, Grantham, Newark and Retford between North East and Leeds services
- Try to balance the calls at Stevenage, Peterborough, Grantham, Newark and Retford so a regular interval service is provided from London
- Try not to delay long distance services too much
- Try not to overload services
It should be noted that there are three trains to Leeds between 1700 and 1800, but only 2 between 1800 and 1900, which means that it would be a bad idea to stop the 1835 at more stations, even if that won't delay the service, because it would overburden the train with Lincs/Notts commuters, while it is prudent to stop the 1830 at as many intermediate stations as possible, because it runs only 10 minutes behind a North East express, and additionally provides through services to the NE from Lincs/Notts.
The new timetable shifts the compromise towards "standard pattern", and in fact makes it harder for some long distance journeys not involving London or Peterborough, but since the standard pattern is designed to be fairly robust*, it should be better for the majority of passengers.
*if EC and NR can sort out their respective maintenance regimes - is it just me, or do EC sets fail more than they did under GNER?
