I agree with the principles of what you say but I also agree with the other reply to you. It is definitely a continuum and we can only impose artificial boundar

I agree with the principles of what you say but I also agree with the other reply to you. It is definitely a continuum and we can only impose artificial boundaries to it; what is mutually intelligible to one speaker may not be to another. However, from my experience of the accents of the Atlantic Archipelago (owning to my political bias here!), I don't think Scots is more different to RP than Scouse or southern Hiberno-English, perhaps with the exception of some very isolated communities.