The reason Africans do better is because most of them (particularly those from West Africa) came here as professionals with degrees whereas the ones from the Caribbean obviously didn't. The Afro Caribbeans have assimilated into western/white working class culture (and with that comes poor academic attainment and low social mobility).The other reason is those form the Caribbean have an individualist culture (Like White Brits) whilst Africans have more of a collectivist one
You know what the biggest difference between Afro-Carribean and Black Africans?
The Africans don't allow colonial baggage to stifle them.
If you see the Africans in acting roles (their traditional African names) aren't stifling them like Idris Elba. To get into acting roles, you are mixing with Luvvies who are tending to be upper classes.
Even the profression of Rugby which is seen as a middle class sport has quite a lot of Black African players with African names.
To the gorah, if you have an Anglicised name, they are asking the question "what are you hiding?".
If we compare the Carribean blacks and African blacks I would say that the whites mingle more with the Carribeans as they have English names and a culture which is slightly more similar to themselves.
However the Africans are more successful academically and economically.
So if you want your kid to have a gora/gori partner then go for a western name but it won't do much for their career.
In fact goreh might ask your kid 'is that your real name?' And they will never be able to escape the classic question- 'where are you really from?'