I don't have a Michael in my Amor/Aymer line, so I'm no help to you there. Sorry. And, I can't see your link because it's a higher subscription to Ancestry than I have.
I suspect that the changes in spelling had to do with the census takers more than the names. Not all of them were very literate, nor were those giving the information, so the spellings were more by sound than anything else. It makes us crazy but it's something we just have to work around.