As a Brazilian, I can say we didn't got the worse treatment in this regard. There are problems, but nothing that completely ruins the characters.
Sure, there was Marvel's Captain "Forsa" (how can someone translate Strength wrong is beyond me), but that was very much as disposable character and even so, he did not have "Brazilian" as a super power, being a generic powerhouse type (not very interesting, sure, but better than having super-soccer or something like that
)
Sunspot is a better example from Marvel. Sure, he was a soccer player, but also the son of a rich family (not the obvious route when one thinks "Brazil", sadly) who became a solar-powered mutant in a very public incident but kept a relationship with his family and girlfriend. I never liked him, but he was a well developed character with much more than being from Brazil to describe him.
As an aside "Thunderbolts" and "Dynamos" are very much not the kind of thing we name our soccer teams. Nor any soccer teams from anywhere I've known (though I hate soccer, so I don't know much)DC has Fire, which is likewise find a not particularly interesting but well developed character. Her original version gained her powers through Brazilian mysticism
(so tells me Wikipedia, I've never seen that story). That seems better, imo, than the later version of amateur model - turned showgirl - turned secret agent (wtf?) that got powers in technological accident. But they are acceptable origins anyway. Her powers and characterization aren't limited to "Brazilian".
There have been consistent problems with her use of the native language for years, though. From speaking Spanish instead of Portuguese, to mixing both, to just speaking it wrong in Portuguese
In the end, despite the problems, many countries had way worse stereotyping going on in their superheroes as presented by US comic book companies.
If GR decides to publish a book of national heroes from various countries, I'd suggest keeping in mind about Brazil:
Portuguese, not Spanish.
There are places other than Rio de Janeiro and the Amazonian rainforest here.
There are surnames other than "da Costa".
It is a huge nation which has been colonized by many different peoples. There is a lot of cultural diversity.
(look up images of the micareta or the carnaval in Salvador and compare with the Octoberfest in Blumenau, for some contrast).
