My problem with a UB replacing the Stadium is that it comes TOO late to matter, really, very very very late. At that time, it would be better if we had a second UU, but I'd like a UU and a UB or UI. I hope I don't see carnival, though, it is sure well known but opens a door to stereotypes, I'm also part of the people who dislike it a lot.
I think the most famous unit we could possibly have is the Bandeirante. Many people here suggested it, even though being a symbol of Sao Vicente rather than the country as a whole, and it was sure during the colonial age, but it would have a nice gameplay. Also, I was thinking about the Guarda Nacional (National Guard), which helped to destroy revolts inside the country, but I think I already said that (or was it to my friend? not sure).
Also, can somebody answer me something? Is their color scheme Bright Green and Dark Green (as in the opposite of Arabia) or Bright Green and Weird Blue?