Quote Originally Posted by Board of Command
Then what about GunXSword? There was a Michael in that too.
As I said, they are using the German pronuciation. If that's the case, then the romaji representing the katakana used is Mihaeru instead, and it's pronounced different than the English Michael. In the end, it's the same name but it shows what's the intended pronuciation of the name given is and the country of origin for the intended name.

As Psyke said, Katakana is used to help Japanese pronounce foreing words and names, so as long as it sounds correct it should be all good.