Every time Cao Cao faced the army, Xun You was the mastermind. Xun You made twelve suggestions, all of which were good ideas. Yan Liang was beheaded, and Wen Chou was beheaded with Cao Cao. Guandu did not doubt Zhang's return, and Xu Huai dug priests next. Xun You is low-key, and his plan is unknown. Only Cao Cao knows. Xun You's good friend, a famous strategist and calligrapher, Zhong You, according to his own understanding of Xun You, intended to bind his strategy into a book, but failed to complete it, and Zhong You died. So much so that Xun You's strategy of "every lesson has a test and every word has a load" is about 12, which is decisive.
If Xun You is Sean of Cao Cao, Yu Xun is Xiao He.
Yu Xun was an outstanding politician, strategist and scholar, an outstanding representative of a big family in the late Han Dynasty, and an official of a noble generation. The History of the Three Kingdoms and the Book of the Later Han Dynasty were successively biographies for him. During the short period of more than 20 years in Cao Wei, Yu Xun helped Wei Wu to pacify Yanzhou and Henan and stabilize Henan. Then, he persuaded Emperor Xian of Han Dynasty to attract celebrities with big names, gradually changed the nature of Cao Cao's regime, advocated Confucianism, and played down the rule of criminal names. Judging from the situation at that time, his strategies of "deep planting", "land reclamation" and "using strangeness" in Guandu were feasible and worthy of being a first-class strategist. Cao Cao changed from weak to strong and unified the north, which depended on Xun's assistance. Yu Xun recommended a large number of talents to the imperial court in his official career, including Xun You, Zhong You, Guo Jia, Chen Qun, Du Fu, Sima Yi, playwright, Hua Xin, Wang Lang, Xun Yue, Du Fu, Xin Pi, Zhao Yan, Du Ji and so on.
Cao Cao's first-line advisers, such as Dong Zhao, persuaded him to drive him to Xuchang, Liu Ye led Wu Jun to Jingzhou, Man Chong defeated Sun Quan several times in Xu Huai, and Jiang Ji broke Sun Quan's tens of thousands of troops in one sentence. Zhong You also excelled in military struggle. Cao Cao's conquest of Ma Chao was based on Zhong You's strategy, and under the pretext of attacking Zhang Lu, it aroused the panic of Mahan in Guanzhong, and then rebelled.
Specific suggestions can't be comprehensive. I can only go to see the outstanding performance of Cheng Yu and Yu Xun in Yanzhou and Jia Xu's plot to alienate Mahan in Guanzhong.