I would not wish to be in a position of cutting Hartford or Penkridge down from 2 to 1tph however.
Agree. The situation at Penkridge with a service twice as frequent in one direction as the other was always a bit silly even if timetablers give all sorts of reasons for it. Similarly at Winsford et al which long suffered from an irregular and infrequent pattern.
Really what is needed is a local service from Birmingham (or the Wolverhampton platform 6 bay if Stour Valley paths don't permit it) to at least as far as Wigan North Western, going via Stoke-on-Trent, Crewe and Earlestown, calling at all stations. A long service for a "stopper", true, but splitting it at Crewe or Stoke would mean unnecessary changes to do short journeys such as Kidsgrove to Winsford (though the numbers for this particular flow willl be tiny, it's just one example).
I doubt there's the paths to have locals from Hartford, Winsford and Acton Bridge to both Runcorn/Liverpool and Wigan though, so that would be a case of swapping one problem for another.
Eliminating the calls at small shacks from services that should be fast, e.g. Liverpool to Birmingham, is the only way to make journey times more attractive against the primary competition of the car. Unfortunately the capacity of our railways is really not up to the task of providing both local and long-distance services effectively. This struggle is seen on many other multi-use two-track lines - the GEML north of Shenfield, the Lea Valley lines, Hitchin to Cambridge, the Chiltern line south of Risborough, and arguably the trans-Pennine lines (in the wider sense).
In the long term, assuming that complete four-tracking of these areas is too expensive as it inevitably will be, and that a timetable where all services call at the same stations delivers an unattractive service proposition, the only other options are to add passing loops and use stock that's faster to accelerate.