Hello,
Molly, Sean, Javier, etc. are all from countries outside America, hence why "[country demonym]-American" isn't needed. Arthur is American, so that's all it needs to say for him.
"Marion" is not Bill's name anymore so it should not be used in the introduction.
I hope that clears things up on why these edits were reversed, as continued edit-warring will result in a block.
Thank you.