BRB has the vastly superior track-record, but Gladiator's top-showings are at WTF levels. I see two possible outcomes: 1) BRB beats Glads after an impressive battle in which the two are roughly equals, or 2) Glads mops the floor with him in a fight that for any other character would be considered PIS, but gets counted as a fair showing because of his powerset (he appears to be one of the only characters in comics whose high-end showings will never get labeled as PIS).