Realistically, yes. But it was an episode of a '60s TV show, made for '60s audiences who had preconceptions about what "Indians" were like -- preconceptions shared by the writers and producers. A lot of TOS aliens, especially in season 2, were just stock '60s TV ethnic tropes transposed into outer space, and this was one of the most literal instances of that. When you watch other '60s shows, you see how much TOS was steeped in the preconceptions and tropes of its time. Who says they aren't around? I still think they're the Vians.