One is engraved with a picture of a fish. The other has some kind of a strange animal engraved on it. The facts of the matter are simple. There are stone-built mausoleums in SA of the same shape and size and construction type. They have names that are very similar.
Chronology is similar.
Except for those scholars desperate enough to try to escape from reality. And there are more illustrations on p. 97, a modern photo, and a drawing from 1882. In SA, some chullpas are built of finely crafted regular stone blocks, like in some of the following images. So here's a rectangular-shaped mausoleum from SA that has size and stone construction very similar to EI tupas. Only the worst hypocrite would deny that there's a close similarity in construction techniques.