Hmm, it was said in the Ouki's arc in the translation I read that Ouki may be more well known but ppl don't know that Tou is as skilled and knowledgeable as...
I think Tou may be as good as Ouki in skills and battle tactics like that quote implied, but Ouki had something else that made him special as a Great General. I think his unwavering will and power to raise the morale and inspire others make him better, which may be equal in a hand to hand combat, but Kingdom places high emphasis on one's ability to boost people up with courage and spirit.