That language chart posted earlier is interesting, but this version says something different entirely:
http://en.wikipedia.org/wiki/World_language
The number of people who live where the language in question is native, versus the number of people worldwide who speak the language, are two entirely different equations.
The reason SH3 had "American" English without German accents is mainly because they knew that someday they might make a US fleetboat sim, and thus the voices were already done. I'm hoping that this is indicative of the same sort of thinking.