...high capacity inter-urban stock like the 185s to be used on the S&C, basically a tourist line? Not a chance.
I agree that high capacity stock isn't needed on the S&C for most of the year, if that's what you mean. You're not going to get much 100mph on it either (maybe in the Aire Valley section?)
185s would be good on the hills, but there's not much scope to speed services up much, given the freight paths, but the low frequency of the S&C means it'd only take three units (AFAICR), so it's almost a rounding error in the grand scheme of fifty one 185s
The various Calder Valley routes would be a better use for them, but the daft franchise commitment to spread the new stock (195s) as thinly as possible means it'd be seen as a backward step by various people/ newspapers/ politicians, even though a 185 would be perfectly good at a medium distance route like the Calder Valley - there'd be some guff about how "our new trains" were being replaced by "cast offs" - or does the "cast offs" argument only work when you can put the word "London" in it?)
195s should really have been focussed on shorter "stoppers" where the acceleration is more useful and their "metro" layout more suitable too. Instead, we tried to tick as many boxes as possible by stretching the 195 fleet to try to serve as many stations/routes as possible so that all the "stakeholders" felt like they were valued/ included/ cherished...
I’d put them on the Leeds-Bradford-Rochdale-Victoria route. In fact I’d pair them up with the North Wales and Bolton, Wigan, Southport services.
Running the Calder Valley services through to North Wales would make a lot of sense in many ways - similar type of stock required for typically similar journey/distances, would remove the need for terminating in central Manchester, could be a half hourly Leeds - Hebden Bridge - Manchester - Chester service, with one carrying on into Wales...
...but parochial politics means it'll never happen (sadly)