1) Cao Cao was never a King. He held the position of Chancellor. He was only posthumously called an Emperor by his son, Cao Pi. 2) The language is telling. "Mere" general implies that it is a position not worth having or held in esteem. For one, I don't believe that classifying Cao Cao as a GG is in any way, demeaning his achievements as a leader. The Battle of Julu was impressive by all means, but the Qin were already crumbling by the time of Xiang Yu's ascent. While that is all completely true, if you haven't noticed, for China, all of the GGs are laid out and organized by era. As Cao Cao is included for the Three Kingdoms Era, there isn't room for a contemporary. That being said, the only GG I would contest is Hou Junji; I'd swap him out for Koxinga or Yuan Chonghuan, but with the former, it's hilarious to have him on the same list with Shi Lang and with the latter, his role overlaps too much with Yue Fei.