Michael is mike Schmidt under a fake identity same with Jeremy, Michael is the brother in fact due to the crying childs death (the thing that fredbear said is a lie because he wants to kill you), it is physically impossible for Michael to be spring trap because he has no reason to go into the suit proving that William is spring trap AND scrap trap (plus glitch trap but we arent talking about that), and finally just because William created synthetic skin in the book series does not mean he can do it in the games.