Biggest example of plot armor in this manga, Aoba and his shenanigans during the second tournament arc are not even close.
The coach guy is supposed to be very rusty after such a long period of inactivity without proper cycles of training camps with a good team. And yet he TKOed a much bigger top-5 Dagestani fighter from Khabib's team (one of the best in world). What is he, Jon Jones-level talent?
I guess the author coped too much that all the recently signed stars from Japanese MMA promotions did not do that well in the UFC, so he needed a win at least in manga. A more realistic scenario to this fight would be something similar to Machachev - Moicano