From the above route, it is not difficult to find that Wargo climbed more than 700 miles of mountains, not directly to Chengdu, but through many passes. Zhuge Zhan, Zhuge Liang's son, could have reversed Gan Kun and saved Shu Han from extinction, because he could have stopped Wargo's attack from the first pass, but he missed the opportunity, so it seems that he didn't think of it at all.
The first pass that Wargo faced was Jiangyou garrison, which was established during Liu Bei's reign to prevent Cao Wei's army from crossing the Motianling to attack Shu Han. At that time, the general guarding Jiangyou was Ma Miao. After Deng Ai sneaked into level tone, he chose to surrender to Deng Ai. Why did the horse surrender without a fight? In fact, Ma Miao is also a last resort. Although Jiangyou is a military fortress, most of Shu Han's troops are in Jiange, where Jiang Wei is hiding, so there won't be too many defenders in such a stronghold.
Wargo's sudden appearance was unexpected. Wargo led more than 10,000 people into the level tone. Even if 60% of the troops were damaged on the road, there were still 4000 people. You can imagine how helpless Ma Miao is in the face of these troops. Without Zhuge Zhan's help, Ma Miao has been isolated. As can be seen from the above, if Zhuge Zhan provides support to Jiang You in time, it may be a result.
However, history does not allow us to assume that Zhuge Zhan missed the opportunity, which led to the fall of Shu Han and the smooth entry of Wargo into the plain. In the end, Zhuge Zhan chose to fight Wargo, and eventually he was defeated and killed, and Chengdu could no longer defend it. To sum up, Zhuge Zhan's decision-making mistakes were one of the reasons that led to the demise of Shu Han.