Based on another thread. Just 5 Fighters. Foreman Jack Dempsey Sam Langford Jake LaMottA Ricky Hatton
Dempsey Lamotta Graziano Tony Galento Sonny Liston All had a street fighting background and you can count on them that they won't run.
Liston as an on-call, "6th man". The Bear was a professional enforcer for the Mob, and once stuffed a St. Louis cop head first into a garbage can.
Id be looking for top fighters/Boxers/athletes who were also known for street fighting prowess as loads of boxers weren't necessarily street fighting tough. the Camden Buzzsaw for example.
Frankly I'd go MMA for a street fighting squad. Fedor Vovchanchyn Overeem Aleksander E Wanderlei If not I'd take a collection of boxing giants. Valuev, Ustinov, Carnera ... that sort of guy. Most "street fighters" are tough when they are backed by 10 friends and/or are obviously bigger than their victims. Dustin Nichols as a 6th man to eat the remains or use as a bowling ball to dash them over like skittles, as the situation warrants.
I don't know what the rules are but if we're talking boxers only: Tyson, Foreman and Liston are locks.
Little Charley Mitchell from the UK was considered the best of the cobble fighters during his heyday. Chuck Wiggins was another . Duran?