I suppose there's a question of how much "change" people would be willing to accept if it meant electrification - e.g. splitting services or diverting them to fit the map of which lines are electrified. You'd get a much better business case if you "simplified" the route map to suit the lines that you are wiring.
For example, on the Calder Valley (by which I mean services from Leeds towards Manchester Victoria through Bradford Interchange and or Hebden Bridge - I'm aware that Bradford isn't actually in the Calder Valley but the phrase seems to cover all trains on the Bradford Interchange line out of Leeds), there are services extending to Hull/ York/ Blackpool/ Chester/ Huddersfield and also via Dewsbury and Brighouse)
If the plan is to wire (just) the main route from Leeds - Bradford Interchange - Hebden Bridge - Manchester Victoria then the most efficient way of maximising the proportion of electric trains under the wires would probably be something like:
- All Leeds - Bradford Interchange - Hebden Bridge services continue to Manchester Victoria instead (no more Bradford - Blackpool)
- The "via Dewsbury and Brighouse" service becomes the services that extends to Blackpool (no more Brighouse - Manchester)
- No more extensions to Chester or Hull
Would that be acceptable to passengers/ politicians though? Cutting Bradford's long established link to Burnley/ Preston/ Blackpool would be difficult to "sell" - given how the various "Stakeholders" of Bradford managed to get the Arriva franchise to promise to direct trains to Nottingham, Manchester Airport etc
Brighouse to Manchester is a fairly slow journey via Hebden Bridge but it's a direct service, so may be unpopular if you were cutting it.
The Hull and Chester links aren't that important in the grand scheme of things - both fairly new - maybe you'd decide that an electrified Calder Valley line would mean that the services should run to somewhere else electrified on the other side of Manchester (e.g. Liverpool)
But how many people want those kind of awkward conversations about simplifying the service pattern to improve the case for electrification? Do you accept losing some of the direct services that you have, even if not frequent?