None of these take a hyphen in English. Simple.
Groot–Brittannië. Noord-Ierland. There’s not much to say about this one. The convention is different in English to Dutch, which does hyphenate these geographical entities.
- English doesn’t even use the hyphen in the demonymic form (North American, South African, New Zealand)
- Not just countries and continents: the same applies to e.g. New York
One to be careful with, as the spelling checker won’t always spot it!
Prevalence: moderate. Anywhere that geographical nomenclature turns up.
Frequency: very high. Dutch authors tend not to realize that the convention might be different, so it’s bingo nearly every time.
Native: no. Quite a good give-away of a non-native text, actually.