Thing about Sunderland is that Newcastle is right on its doorstep, meaning that the majority of people will choose not to spend their time there. Making the town not only shit, but also deserted by the majority of people. Hull and Stoke are more isolated in that respect, so if you live there you have to spend your time there. Making those two cities a bit more appealing, in a "we're all in this together" kind of vibe.