Some of the assumptions about language in this paper are just total junk lol... this one is particularly good "...and for the
rest, overlapping vocabulary is a good proxy for similar languages" - this is so wrong I don't even know where to start. The grouping of language by family is also bizarre, the genetic groupings they give for each language are at all sorts of different levels. They say that cultural and geographic proximity was also a factor in grouping, but e.g. the Mongolic and Kra-Dai families have essentially nothing in common apart from the fact the people who speak them look sort of similar to a European. Grouping the Afroasiatic languages Somali and Amharic with the Niger-Congo set also seems like the only criterion was the physical appearance of the speakers...
There is also no way for a reader of the paper to judge the effectiveness of the algorithm. They cite this evaluation of "semantic accuracy", but nothing about the design of the task, participant selection, example data.
This paper is pretty much junk science. Even the reference section is amateurishly formatted