> But someone in a remote part of England will get the same advice as someone in central London,

The current system might not have perfect geographic granularity but that doesn't mean it isn't preferable to one that gives advice from half the world away.

> Human biology is the same, diseases are the same, and the difference in available treatments is not usually all that different

Accepted medical definitions differ, accepted treatments differ, financial considerations, wait times and general expectations of service vary wildly.

England is not "half the world away" from Scotland.