There was a SemEval competition about having vectors that are both accurate for 5 individual languages and aligned between all the pairs of languages [1], where Numberbatch was the first-place system [2].
The fastText_multilingual system does have something going on, that it can discover multilingually aligned vectors after the fact for a system that was previously separate for each language, and leaves it "the same system" in a sense. But incorporating the ConceptNet knowledge graph also gives you a multilingually aligned system.
[1] http://alt.qcri.org/semeval2017/task2/
[2] https://blog.conceptnet.io/2017/03/02/how-luminoso-made-conc...
The alignment procedure is completely agnostic to what word vectors you use. It only requires that cosine similarity is a good distance metric. We used fastText because there were lots of open-sourced vectors available...