Nice and enlightening statistics!
And yes, the original question was not for a subdivision per language, but per hub. You are right.
But how would that work with , say , the EHAM hub? There's 8 Dutch guys, so they will most probably "belong" to that hub. Let's count in the Belgian force of 6 people to that hub too (assuming they speak Dutch, not French
) But what if (hypothetically) 2 more Portugese guys and three Hungarians also chose EHAM to be their hub, for whatever reason. What would become the Hub-language? There's really not that many people around in the world that speak Dutch ... or Portugese ... probably even less that speak Hungarian ...
So the "per-hub-one-language subdivision" probably would not work either. You would end up with a subdivision per language, irrespective of the hubs, anyway.
So that's more or less the reasoning behind why I picked up on your "nationality groups" idea (thus leaving the hub groups idea) without giving it much further explanation. It did swing the thread off-topic a bit, though.