No they don't. Which makes your logic about pronunciation even more absurd. Liverpudlians are heavily mixed with Welsh and Irish hence their English sounds like that - the English spoken in Kenya is actually better English than scouse if you consider the most important tenets of a language - grammar and vocabulary.......yes, grammar and vocabulary makes a language, not accent.
No two groups of people pronounces a language the same way - so how do you establish which group is pronouncing it correctly? That's why we have standardized ways of pronunciation which is impossible to achieve at all levels - even to the natives.