>>535094668
Fighting in real life and manga are not even remotely comparable. In manga characters often do big, flashy attacks that are effective because few in the setting know how to dodge and punish (Look at how many times in OG characters did a jumping kick before they could fly), while in real life you're mostly better off doing quick attacks so your opponent doesn't retaliate. Strong and slower attacks can work and knock out your opponent, but you can lose your balance and whatever.
The fighting styles are just incompatible and incomparable. On top of that, boxing itself is way too restricted as far as fighting goes (Can't kick, can't use elbows, no punches below the belt, etc), so Muhammad Ali, even if he were that good, would not do as well against someone else from real life who's very good but fights in a less restrictive martial arts like Muay Thai.