Back in the 80's, researchers also worked on the concept of a "bridge" language; that is, first translating a text into a language with a simple grammar, few homonyms and other beneficial traits, and then translating again into the target language. One of the bridge languages was Aymara, but then Google's statistical model took over. You can almost tell how much material Google has to work with. For example, Mandarin<=>English translations are pretty good, while Thai<=>English is usually unintelligible.