Given that Margo's best weight was 147 and Chavez is 160, Chavez would be too big for Tony. If we are talking a pound for pound fantasy where all things are equal and they are equal at their best weights and both primed, Tony beats his ass with his relentless workrate, both have mediocre at best defense, but Tony threw many more punches. Neither guy has one punch KO power, each getting KO's by wearing opponents down. Tony just wins on workrate.