Well as a regular user of the TPE north route this is a topic I am interested in.
Current best journey time Man Pic to Leeds seems to be 49 mins which for a 42.75 mile journey is an average speed of 52.3mph
Current best Man Vic - Leeds is also 49 mins for 43 miles according to NRT, 52.6mph I would have thought that Man Vic - Stalybridge would be shorter but obviously not.
Given current infrastructure I would expect that either alternative route would be slower, certainly on diversions, when Stalybridge was closed a few years ago non stop Leeds - Man Vic via Brighouse and Calder valley were around 1h20m
53mph for an 'express' inter city service is very poor. The current mainline between Leeds and Manchester is I suspect at its capacity limit, and very few places where fast trains can overtake stoppers. End result is late running, 5-10 minutes being common, due to 'following a stopping service'. This is usually recovered by York as there are recovery times at York and Leeds in current timetable.
Current push to run more frequent trains isn't the answer, this will just make timetable even more fragile, 4 longer trains per hour would be easier to path, and more reliable. 15 min intervals instead of 10 mins is only another 5 min wait.
Add to that sending everything through Man Vic is another bad move, if you have an onward connection it is likely to be from Man Pic, which will be at least 10 mins from Man Vic when the Ordsal chord opens. It reminds me of the old days when you either changed at Stalybridge for Stockport or wasted about 20mins getting between Pic and Vic
My own recipe for improved York - Leeds - Manchester service whilst hopefully keeping cost under control:
Restore fast through lines at Crossgate and Dewsbury.
Make passing loops at Slaithwaite (current formation appears to be in the middle of the old 4 track layout.)
If a bit more money was available:
Keep majority of trains routed direct to Man Pic, 4 tracks could be restored on the Guide Bridge - Ardwick section, with a higher line speed, to segregate stopping trains. There doesnt appear to have been much encroachment on the old 4 track formation.
4 tracks around Mirfield, there is room, but Mirfield Station with its big island platform would be in the way, and would require redevelopment.
I think maximum speed between Leeds and Manchester is 75mph, with a little bit of 85mph west of Huddersfield. There probably isnt much scope to increase this, but at least get trains moving as near this as is possible within the existing corridor.
42 mins (60mph av) should be easily achievable.
I actually don't think electrification is going to deliver a faster or more reliable service, may cheaper for TOCs to run, but thats all. What if electrification money was to be spent on small scale improvements like I have mentioned?