After more than a century of litigation the Oneida won a lawsuit at the Supreme Court that allowed them to buy their own land back.
Everything that's being tossed up as a reason to not give the land to the Indians in Brazil has been tossed up as a reason to take away Oneida land, kick them of their land, prevent them from even buying their own land, or living on their own land that they've bought!
I'm afraid I've gotta' side with the Indians in Brazil ~ but with a word of advice. You must immediately engage the people who helped you in a law suit to KEEP THEM OUT.
Might even think about refurbishing that poison dart/blowgun technology as well. They mean you no good at all.