It's possible to identify a surprisingly large number of matching words by learning a linear transformation mapping word vectors from two different languages in

It's possible to identify a surprisingly large number of matching words by learning a linear transformation mapping word vectors from two different languages into the same space (e.g. https://arxiv.org/abs/1805.06297 https://arxiv.org/abs/1805.06297 ). But the problem with ancient languages is typically that there's not enough data to usefully constrain a large enough model. Doubly so for undeciphered scripts where scholars might not even agree on how many different letters there are.