Oscar is mexican american because he is a direct descendant of his mexican family , mother and father,

Im pretty sure roger and floyd sr were born and raised in michigan..

Say your parents are scotish and your born in england..That makes you half scottish..

But say your born in england and your great great great grandpappi is scottish.. that dont make you half scottish.. that makes you so little scottish that its not worth mentioning.. Same with roger i suppose..