UK accents go a lot more local than that!
I'm from Lancashire, and people tell me I have a "Preston" accent (which horrifies me, but kinda true - Lytham) whereas I can spot someone from East Lancs such as Burnley or Colne quite easily. You also have a Mancunian accent, and a Scouse accent. I'm sure my online friends from the Manchester/Preston area will confirm, or otherwise.
I can also spot someone from Leeds as opposed to someone from the East Ridings or Sheffield in Yorkshire.
In London you have Cockney, Norf London (Arsenal esque) kind of accent, and also, from my days of living sarf of the rivva, someone sarf landon.
I can (usually) spot the difference between someone from Glasgow and Edinburgh, but not the rest of Scotland. Wales and Northern Ireland I wouldn't know if they have regional dialects within them.
I still think the Brummie is the worlds worst. I used to live there and it rubbed off onto me very badly. Up the Villlaaaa!