1. Ousen
A wild strategist, a tactical mind comparable to the one of strongest Great Heaven in history, Riboku. He is in fact constantly matched up against and paralled with him. He also has parallels with Hakuki, the (imo) strongest of the old Qin Six. And EoS Ousen will be even stronger, probably the strongest commander ever, and the final guy that Shin overcomes (taking his place as the GOAT general). In general new gen > old gen and Ousen embodies the best of the new.
2. Shouheikun
This man has immense hype. A top brain, he's Qin's Head of the Military Affairs. He's also often paired up against Riboku. Aside from his utter genius, he's also a talented warrior, one of the very best in the manga. Many don't rank him quite that high but I honestly think that his raw talent is superior to that of every member of the old Qin Six and he only loses (very very slightly) to Ousen.
3. Hakuki
The leader of the old Qin Six, a man who terrorized China. While Ouki got the "rumor" of the being the best of the old, I think that it is for Hakuki that Hara reserved the most factual evidence on that. Needless to say, this man was an absolute freak.
I see them this way but putting Hakuki #1 or Shouheikun #1 would also be fine, they are really close.
Okay, let's continue:
4. Ouki/Koshou/Tou
I have those three on the same spot. Everyone knows Ouki, Qin's Monster Bird, a legendary Great General from Qin's previous gen. Koshou was also part of the old Qin Six and was a genius of warfare, to the point where there were rumors that the other five were the appendages in his plans. He also taught to current Qin's military chief Shouheikun.
Tou is man whose true power is still kept hid by Hara after hundreds of chapters...and this is scary. Ouki also said that Tou was never below him in the first place.
5. Duke Hyou
The apex of the instictual commander, he crushed many strategical generals. The man received a big amount of recognition in the manga but the most impressive piece of hype comes from Riboku himself who called him a man above his understanding of war, after the Duke's "unthinkable" feat of seeing through his "current" tactic through instinct alone.
6. Moubu
This man, him and him only, is somehow able to have his army beat tactics through pure might, tactics that if any other Great General tried to tackle too with might alone...he would utter fail. In an era of tactical supremacy, Moubu still manages to be one of the greatest Great Generals in China. His understanding of warfare "runs deep" and he is capable to use even complex formations on the occasion. Qin's greatest offensive power in history.
7. Yotanwa
The King of the mountains, comparable to what Sei himself is for Qin. A very strong strategist and an outstanding leader. A top tier duelist too. Her armies goes nuts just from her presence, crushing the morale of her enemies. She won a truly extreme battle in the Western Zhao arc. As one of her (previous) Quanrong enemies said, Yotanwa is someone truly worthy of being called a King.
8. Kanki
Qin's demon. This is a man who never formally studied warfare and yet thanks to his own cunning and bandit like experience was able to climb up the ranks all the way to Qin Six. His thoughts elude even Ousen's and he has some shocking feats under his belt, such as his utter defeat of Great General Kochou with a 3:1 number disdvantage. In Northern Zhao he fooled and almost killing Riboku despite the context he had found himself in. However some of his feats were very situational, something I've talked about in the past. Still, there's no denying his legendary status. Kanki's warfare is so unique that I think he at least a shot against pretty much everybody in the manga. More than some other Generals who I rank above him.
9. Kyou
Kyou was described as a genius of war, the blood of King Sho running in her veins. Ouki was her mentor and she got a lot of praise from Renpa and Kyouen as well. She was quite young when she died and yet she had achieved a lot, becoming one of the Qin Six and big threat to the other states.