Had a little conundrum along the way. The artist who created the Super Metroid manga in Nintendo Power was Benimaru Itoh (he also, incidentally, drew the Star Fox manga adaptation around the same time, but I didn't have room to get into that in the article).
Now, there's an Ashura Benimaru Itoh listed as a performer on the Mario & Zelda Big Band Live CD (2003). I suspect it's the same guy, but couldn't find any reliable confirmation. If anyone knows of a credible source one way or the other, please let me know – it'd be quite the nerdy piece of trivia, if true.