Firstly, I didn't just focus on stats this time, I even mentioned a line from the most powerful and knowledgeable character known.
Second, it should be obvious, since even our dear BH has already recognized what the MC's flaw is, experience and technique. Characters with lower stats are capable of fighting and defeating characters with higher stats. I've said it myself before, if MC had fought better and thought more, he would have done much better in the tournament fights. And that's why we still have characters superior to MC, they fight better and have more experience, plus transformations and empowering Arts are still a danger, even TW makes this clear, Yang Gan literally uses two transformations at the same time, one of them boosts his power for every Devil Breakout he has and as a Yang he's probably experienced this and has been experiencing it since he was 13~14 years old.
I imagine that BH also has transformations or something like an Art that invokes third-party/ancestral power. I suppose He Mei's poison was stronger than we thought, He Mei herself thought that BH wouldn't even be able to get up and fight after the poison spray, of course she was wrong.
BH did acknowledged that the MC lacked experience but while you thought he meant it purely as a flaw. BH himself instead realized it only meant we had something even more dangerous. Something that made him offer a draw. “True geniuses of the Houtian have too many ways of keeping themselves alive, and too many ways for you to die.”
BH isn't a counter but is instead an example of MC managing to fight evenly against someone who is stronger, faster, and has decades more experience. “That poison cost me about a third of my power, but I’m still faster, and I’m still stronger than you. You're keeping up with me solely by relying on your instincts an incredible feat, by the way.” Certainly, there isn’t a single being participating in the tourney who can claim to have more fighting experience than the Blood Hunter himself.
As for Gan, Complete Asura is far superior to whatever thing he got going on considering how desperately Bohai desires it and how much he values it. He even got mad enough to try and kill the MC about it despite knowing MC was under Butterfly protection and he himself likely allying himself with her. This would lead to
"The hit staggers him. The second, coupled with the third, knocks him down. He suddenly begins to bleed from seven orifices, his anger giving way to horror.
"I ap-apologize." — he says, bowing his head — "I forgot myself."
The tension in him then disappears and he wipes off his blood, giving you a hate-filled look."
The difference in base stats aren't minor either if Gan stats are still cannon. 15k means we have 33.33% more than his strongest stat. 36.67% for his second strongest and it only gets worse and worse from there. Not to mention how shameful how much effort we had to put against a 17th ranked person like Mogui