If his claim is they have the most multilingual speakers, then the proof would require them to collect data on how many individual dubs use more than one language. It isn't just that they can, it's that they use 2 or more language in their lives. This is according to the definition of 'multilingual speaker'.
Do they collect such data?
The fact that they've translated bibles and all that other junk is irrelevant to proving this claim, though I'm sure they won't let that stop them.