You are absolutely correct. There are no Cantu’s in Spain because they fled. They were Jewish and were persecuted for their religious beliefs. When I was in Madrid I went to a place that sold coat of arms for surnames and they told me
Cantu would not be found in Spain because it was not a authentic Spanish surname. They settled in Italy when they fled their mother land then some settled in Spain briefly than fled to Mexico settling in Tamaulipas and Nuevo
León, Mexico. That’s what my research shows.