The country is the USA, but not Texas and no of the fighters are related that I know of, so they are definitely not brothers. Remember it is the 80s, they may of all come from the same stable...
Here's a couple to leave you with: Last fight between two undisputed world champs? 15 round 'undisputed' world title fight in past 40 years in which EVERY round was scored even on one of the judges cards? What street does Earnie Shavers live in?