my first thought was zale by tko...just too strong and tough to be bullied and has a sizable punch to get to barkley. but yet again you had to have good fundamental skills to get to iran. duran,toney,olijade all had the tools to get tag him and not get hurt. zales punching power is also a bit overated (isn't his real strong point is more precise) because he scored a great one shot ko over graziano. it's his toughness chin and willingness to trade that wins him the fight. wearing the guy down. the more i think of it the more i see barkley winning. if you try to out muscle barkley you get floored. you have to box and move then counter when he come in...zale cant do that so a tko form barkley i think is on the cards.
Just watched Benn and Barkley ,Barkley was easy to tag ,Zale was troubled by good boxers ,Barkley was not one.Zale by late ko.
He came in cold against Benn, who was allowed to flagrantly break rules without penalty. Benn almost got stopped anyway. Barkley did show more skill against Duran than he had before or after in my opinion... that version may be favored against Zale. My gut still chooses Zale though... or perhaps I'm just being sentimental.