Four kills is not terrible, the terrible thing is that the tower was stolen when the four kills were killed.
What is most important when marching and fighting? The most important thing is the stability of the rear, because even if you lose, you have a way back to go, and you will not die tragically.
But once the rear is lost, then you are homeless, and the only thing that awaits you is death. When Cao Cao went out to fight, he never took Xun Yu with him, so what was Xun Yu doing?
Xun Yu's main task was to guard the rear and help Cao Cao watch over his home, which was more important than anything else. With Xun Yuzhen guarding Xudu, Cao Cao could fight with confidence and not have to worry about being "stolen from the tower".
Before the Northern Expedition, Zhuge Liang knew the importance of stabilizing Chengdu, so he first marched south to stabilize South Central, as long as South Central did not rebel, Zhuge Liang could single-mindedly carry out the Northern Expedition.
When Zhuge Liang was in the Northern Expedition in Hanzhong, he heard that some people in Nanzhong had rebelled, which naturally affected his Northern Expedition, so he wanted to stabilize Nanzhong and prevent this kind of thing from happening.
In the spring of the third year of Shu Jianxing (225 AD), Zhuge Liang personally led an army to conquer Nanzhong and made Nanzhong submit to Shu Han. This area of Nanzhong is far from the Central Plains, disrespectful to the king, ideological and cultural is still quite backward, gathering a large number of barbaric tribes, of which the two most famous tribal leaders are Yong Min and Meng Yue.
If Zhuge Liang forcibly used troops, he could only temporarily stabilize them, but they would rebel in the future, which was obviously something that Zhuge Liang did not want to see. Zhuge Liang wanted to cure the root cause, and he wanted the Nanzhong tribe to submit to the Shu Han and submit to it forever.
Ma Mo advised Zhuge Liang to "attack the heart first" and make them completely submit. In order to completely conquer the Nanzhong tribe, Zhuge Liang captured seven and seven longitudinal Meng, so that Meng Yu had no face to fight zhuge Liang anymore, and could only strike the army and make peace, and submit to Shu Han.
There are many big surnames in Nanzhong, and they have lived here for generations, such as Yong, Lou, Cui, Meng, etc., and Zhuge Geliang focused on supporting the Chuan and Meng families.
According to the "Huayang Guozhi", "In the final light of the world, the south does not dare to rebel." After Zhuge Liang conquered Nanzhong, they no longer rebelled.
Among them, the surname of Cuan should be emphasized, this surname under the support of Zhuge Liang, and the surnames of Meng and Huo became the three major surnames of Nanzhong, and later the surname of Meng and Huo annexed the two surnames of Meng and Huo, dominating Nanzhong and becoming the local family clan.
According to the New Book of Tang, the surname Ofe remained in Nanzhong until 523 years later, in the seventh year of Tang Tianbao (748 AD), when the Meng clan of Nanzhao rose, and the Meng clan destroyed the surname.
However, in the past five hundred years, the surname has developed its own culture, and has also formed its own script, which is called "Cuan Body" in history. The culture and writing of the surname have become the main materials for the study of local history, and have become part of Chinese culture.
The Japanese people are very respectful of Chinese calligraphy, and they come to Yunnan specifically to study the body, and in order to show sincerity, they also bow down to worship.
References: Romance of the Three Kingdoms, Chronicle of the State of Huayang, New Book of Tang, etc