Tommy vs Koba : who do you think would have won ?

I think it would have been interesting variant way to write the movie if Tommy had to face Koba and won but unlike his previous fights far from effortlessly and the fight is long and brutal going both ways and after eking out his win its obvious he is in really bad shape while Brendon wins against Mad Dog Grimes with only moderate difficulty.

There could be a scene in the hotel room where Pappy is worried and tending to a very weak Tommy and saying "I think some of your ribs are broken you cannot fight again until you heal" and Tommy ordering Pappy to not tell anyone about the ribs.

Tommy going into the final fight in terrible condition would make him losing to Brendon more believable. My idea is that EVEN THEN Brendon is the underdog but under normal circumstances he would not stand a chance against Tommy.