Which particular through connections would you like to sever? (That is off topic by the way)
I guess the equivalent of Cardiff to Manchester as a 150 is TransPennine using 150s to Newcastle? Maybe the Saltburn train if Newcastle seems a bit bigger than Cardiff? Worth remembering too that TPE do have Mk5 which are new, not hand-me-downs, and have phased them out because unreliable microfleets are not progress.
I guess it is hard for rail enthusiasts to think that normal passengers prefer a 197 on a direct train than loco-hauled stock that breaks the connection and gets replaced with a 150 (or borrows the 197 from a direct train so the 197 gets replaced with a 150). I find it laughable that people defend TfW when this whole thread is "which of the booked diagrams are actually running?"
We are told there are changes coming to the timetable, but this shambles has been going on for more than one timetable change already. It seems so long ago we had a reliable 175 service on the Marches which connected West Wales
Your beef is with TfW, not me