Speaking of, Chu is introduced as a military juggernaut superior to every other kingdom due to its size (pause) and the sheer number of people they're able to muster. The only thing keeping them from crushing Qin is internal strife from maintaining power over the various cultures under their banner and the fact that they border multiple kingdoms, all of which they're running the fade with. So you've got your biggest genius opp Riboku and your literal biggest opp working together and that's disregarding everyone else, Qin is cooked.
When it comes to Cheng, I agree with you wholeheartedly because dude is basically a whole ass coward and I felt like that reflected badly on his whole kingdom that THIS is the best representative of your Kingdom. He's obviously a genius and effective AF when given the chance to utilize chemical warfare but you put an enemy in front of him directly and he's not built for that, at all. Zhang, on the other hand, exemplifies what the core of Qin's foundation is all about with the pride and determination to die on his feet and pushing his Kingdom forward despite being an also ran in terms of the actual military titans of his era. Even though it's that same pride and adherence to "the proper way" that held him back, it's still a hell of a statement that Qin 2nd tier bench player outperforms their star player on the biggest stage.
It's good to see you're picking up the vibe with Kanki/Huan because this guy gives off heavy villain vibes but he's one of our best Generals. Like I said before, this character is one of my favorites because he's got so many facets and there's a lot we still don't know about him. Guy seems like an entire scumbag, his inner circle seems to be complete scumbags and bloodthirsty deviants and they stand out amongst the more typical honorable Make Qin Great Again types in the lead. You never really feel comfortable with him in the cut BUT you'd rather have him pointing that malevolence at the enemy than you, so that's a wedge of realism because not every talented leader and General is a good person and obviously the Kingdom knows that. The difference between him and the mustard gas coward is they made sure he's held in check by honorable peers and if it breaks down, he's willing to go get it out the mud. Still, I wouldn't trust him.
Wang Sr? A whole mystery and I wouldn't trust him to watch my dog.