The real science has already been done though, hasn't it? It was already posted with the cast separated based on locational creation and sales is kinda a tricky thing to work with. You'd have to factor in population, the titles availability, and what not... So I'm not doing all of that. Ha-ha. I think Locational Creation is a fine way to show which character represents what because, for the most part, the character gets the most fans based on where it was made.
Yeah, I don't know why OP even went by sales in the first place (let alone sales of the first game alone). By all accounts previously, a character's been considered Japanese if he was, well, made in Japan.
And to address the topic of the thread (I don't think I actually did so yet), Japan could definitely use another character or two, but then again, so could Europe.