A route that already has 2 trains per hour from Leeds that take 45 minutes from Halifax to Manchester.
I'd love a faster service to Manchester but the way to do it isn't by skipping two stations that Northern call at, but by raising the linespeed and other infrastructure improvements.
There is rationale for more faster services between Manchester & Bradford.
If you could achieve a stopper that could do it in half an hour or less then, but I doubt it.
Using the Calder Valley may make it unnecessary to build a new line to Huddersfield, although the benefit with that line is improving connectivity between Bradford & Huddersfield!
I presume you would have all services stop at Walsden, Sowerby Bridge and Mytholmroyd, if you could have your way?
If it was possible, how about having a half-hourly semi fast services, but then everything else stopping at all stations?