That, uh, doesn't make any sense. "Anime" isn't limited to only one style, and American characters have been done in what most Americans would consider an "anime style" many times. For instance, there is a series of Batman manga that was released in Japan. Also the cast of Capcom's Marvel Comics fighting games (X-Men: Children of the Atom, Marvel Super Heroes, Marvel vs Capcom, Marvel vs Capcom 2) are done in a very "anime" style and it worked just fine. Looked great, in fact. On the other side of the coin, some very "anime style" things like Voltron and Battle of the Planets have been given relatively successful American comics, drawn in a relatively "American" style.

When we've alredy seen Jazz drawn in several different styles within the games alone, it doesn't make any sense to say he can't be done a certain way becuase he's a certain style of character. No sense at all.