I'd change it to Malachi Aiden James. I think that sounds better. I'd definitely legally change it, though. I had a friend whose FN was Mary, and her parents had always intended to call her by her MN, Caitlin. It was just an annoyance to constantly correct people - no, I'm Caitlin. I would keep James in there, still. I like the way the three names sound together...Malachi Aiden James is lovely.