It sounds the same to me , in fact one of the lads at college was called geordie in our block of flats even though he was from redcar , he hated it
Can you tell the difference between a pontypridd accent and port Talbot? I cant
Oxford and reading are close to london but the locals sound like they are from the west country . I used to live in headington and cowley in oxford and it was like being in bristol
In general , accents are determined by immigration , newport has that rewnd the roundabout twang on certain words because a lot of labourers from the west country and rural monmouthshire settled there and joined the seaport accent which is like cardiff , to give you cewnty
In the united states Minnesota had a lot of Scandinavian immigration hence the accent seen in the film Fargo