There's no guarantee the Liverpool or Man Airport to Bradford services will carry on to Leeds. All we know so far is that there will be a Chester to Leeds service almost certainly routed via Bradford, thus leaving the Southport-Leeds service to go via Dewsbury. It wouldn't surprise me if one of the Man Airport or Liverpool services terminates at Bradford, with the other carrying on to Leeds.
That would leave 4 trains per hour between Halifax and Leeds (1x Blackpool, 1x Chester, 1x Liverpool/Airport and 1x local) and 4 also from stations further west, the Southport via Dewsbury service replacing the local from Halifax. That is plenty. It's quite likely there will be at least 3 stopping trains between Manchester and Rochdale, and at least 2 between Rochdale and Todmorden, again that is plenty.
I meant either 3-car 170s or doubled up 2-car 170s. So either 3 or 4 carriages.
I think you are guilty of taking the franchise announcements far too literally. They were written for public relations reasons and prominently entitled benefits, aimed at the press and travelling public, not the exact specification of services required by members of this forum. The Calder Valley services have since since Northern Hub days been described as Bradford to Manchester services, both to distinguish from TPE Leeds to Manchester services and for the very good PR reason that Bradford is prominently mentioned.
Even in this imprecise specification there are 6tph from Halifax to Bradford - 3 from Victoria, 1 new service from Halifax to Leeds, and the existing services from Blackpool North and Huddersfield (plus a few Grand Central trains). The current service is 4tph from Halifax to Leeds and will definitely not be "plenty" given future growth - these services are already full running into/out of Leeds in the rush hour with the maximum length 4car trains.
While it is possible for some trains of these 6tph to terminate at Bradford, it would seem unlikely. A terminating service would presumably require around a 10min layover, rather than the current 2 or 3 minutes and reduce capacity. Certainly Grand Central couldn't park their trains there for prolonged periods as they do now,
Finally the business case for the infrastructure interventions on the line (Halifax 3rd platform, Bradford remodelling, Leeds capacity, improved headways) depends on 6tph serving the Halifax to Leeds corridor. Why does the HLOS for CP5 specify a requirement for Leeds to support 2 extra Calder Valley trains if the current 4tph is "plenty"? Why does CP5 specify a turnround to be built at Micklefield (if East Leeds Parkway isn't built) to meet this requirement?
Without knowing exact seating numbers, wouldn't 3 car 170s represent a loss in capacity compared with the 4 car units currently used in rush hours?