Wei Yan's ingenious plan of the meridian valley has a very low probability of success. Once it is successful, it is very likely that the Shu army will be trapped. Therefore, Zhuge Liang did not cooperate with Wei Yan's plan. Zhuge Liang's real idea was to devour Cao Wei step by step!
Many people see the strength of Shu Han compared with Cao Wei, and think that Shu Han can only defeat Cao Wei by scheming and taking the initiative to openly attack, and Shu Han can hardly be Cao Wei's opponent. But everyone ignores the fact that Shu Han can't afford to play at all! The loss of Jingzhou made Shu Han lose nearly half of his land, and his overall strength was greatly reduced. After the battle of Yiling, the elite troops of Shu Han suffered heavy losses and were almost wiped out. Although Zhuge Liang successfully reversed the situation and brought Shu Han back into the formal world, Shu Han was not the original Shu Han at this time. At this time, the overall strength of Shu Han is very weak, and there is no way to gamble!
In short, Cao Wei is rich, and this man can't afford to lose, but the ancestral home of Shu Han is too small for him to play! Zhuge Liang can really play tricks on Cao Wei, but who can guarantee that he will win by playing tricks? Once the plot fails, Shu Han is likely to fall into the land of perdition and perish from this country. In this case, as a qualified politician, how could Zhuge Liang dare to gamble?
Comparatively speaking, attacking Longyou is a good choice! Cao Wei is rich, but in Longyou, Zhuge Liang's 100,000 troops, or people with greater advantages, will certainly be able to annex Longyou and improve the comprehensive national strength of Shu Han as long as they can stop Cao Wei's reinforcements. In this way, Cao Wei was annexed step by step, while Shu Han continued to grow, Cao Wei continued to decline, and winning or losing was particularly unknown! So why can't we defeat Cao Wei?
On the whole, Wei Yan's whimsy of the meridian valley looks very good, but its enforceability is very low! On the one hand, the meridian valley is not easy to walk and is very easy to be ambushed. On the other hand, even if you cross the meridian valley, you can't just get Chang 'an. As we all know, the probability of success in Woods Valley is too low for Zhuge Liang to allow! Of course, there are two other reasons besides the low probability of success of this scheme itself, and Zhuge Liang often does not cooperate! First, the comprehensive national strength of Shu Han is weak, and people's hearts are floating, so Zhuge Liang dare not gamble; Second, even if you get Chang 'an, it is impossible to capture Xianyang and move westward. Then the Shu army was besieged on all sides. Comparatively speaking, swallowing Cao Wei is the best way to succeed!