Tell me about it, I used to have to go to the parades when I was very young because my gran lives in a 'protestant' neighbourhood, used to really scare 8 year old me, lots of dangerous drunk people, police in riot gear, that wouldn't be normal to anyone else but to us in northern Ireland that's just a tuesday. People that come here from England are normally a bit worried when the see 3 meat wagons going up the street lol
Much like saying "a southern accent" or "an American accent "There may be a lot of variables but there are also many commonalities that make for easy funny voices/movie characters.
Also a little like saying "south east asian people". I cant tell a Laotion person from a Vietnamese person, but if you're from there, maybe you could. Familiarity sharpens the specifics, ignorance blurs the subtleties and specifics.