The state of Chu is an enormous obstacle in Qin's objective to conquer China. But just how powerful of a nation Chu truly is and how hyped should we be for it? Let's go in detail.
You mentioned Rinbukun does crack, which is true
But we can't really completely ignore what he said, Rokuomi also reinforced his argument
I'd say, on average Chu's generals are stronger, specifically when it comes to martial prowess as it is easier to find better physical specimens among the southern monkeys seeing how their population is just massive. Not so much strategically, especially when you have guys like Koshou, SHK and Riboku teaching generations of Qin and Zhao about warfare.
And when it comes to quality, then Chu will never compete. In that regard Qin easily has the best policy
There's a reason Chu never bred extremely competent generals like the Zhao Heavens or Qin 6, aside from the Tiger of Chu that is.
They've been bottled up in their holes for far too long and never had a major role in the warring states compared with states like Qin, Zhao and Wei, so far at least. That said their numbers more than compensate for this lack of quality.