The 'HR bods' don't have to live within the hour, they are not safety critical, don't have to book on at 0300 or book off at 0130!
The rules are there for the nature of the job.
As to relocating, I wonder how many people have said they would relocate, were taken on in good faith, but continued to travel long distances to and from work instead of moving home? I understand why, as relocating is simply not possible for some people, and can be an easy or very difficult thing to do depending on circumstances. But perhaps Northern have had their fingers burned once too often?