sorry, that's been misunderstood
the Bradford/Harrogate trains would make up the Leeds' compliment, while the Scottish trains would make up the Newcastle compliment. Basically I envisage 1tph to both Leeds and Newcastle running as a stopper (Stevenage, Peterborough, Grantham, Newark, Retford, Doncaster, York, Thirsk, Northallerton, Darlington, Durham, Chester le Street) with longer-distance destinations providing the fast.
E.g. the Bradford F Square service gives Leeds a London service with a single stop, at Doncaster. The Aberdeen service gives newcastle a two-stop service to London, at York & Peterborough.