English is a much broader accent, as its harder for foreigners to pinpoint exact accents like Welsh or Scottish, where in GB you may easily distinguish between them as you're in direct daily interaction.

Same goes for New Zealand accents overseas, quite often people mistake it for Australian, yet New Zealanders are fiercely objective to this generalisation (love/hate affair with Australia, with a deep seated history in competitive sports etc.). Obviously a New Zealander could immediatly distinguish between his accent and an Australians, but it is much harder for foreigners (through no fault of their own)