Talking about this fight... It really makes me wonder how much thought Nicky puts into deciding stat checks. I mean, if he really, really thinks "how powerful can the normal MC without talents, itens or perks be at this point?", since this is apparently the MC on which the author bases his decisions.
I say this because the fight against BH isn't easy, not if your MC really has no talents other than Regeneration, nor any items or perks. In fact, at this point in the game, on normal, there's no way the MC can have gathered enough EXP to pass all the Stats Checks of the fight, no matter how well the player has accumulated. Speaking from experience, when I tried it with my "simple MC", I needed a lot of prior knowledge, knowing which stats you can fail, using Infuse at all times, etc.
My point is, this is a very difficult fight, in which Nicky seems to have made a real effort to make it a fight that "the current MC can win, but with a lot of effort", both narratively and mechanically.
This is not repeated in the other fights, because, again from personal experience, even the "simple MC" can have stats far superior to those required during the fights at their respective points in the story (mechanically), which is not reflected according to the narrative, where the MC seems to be almost always suffering or getting beaten up.
Edit: Just to be clear, if you don't invest in CHR, you should be able to pass the stat checks without too many problems. But, if I'm not mistaken, without enough CHR, He Mei will kill the MC soon after.