SlickSlicer wrote:I don't know about the novel.
Historically Wei seemingly could have trampled over Shu-Han "at any point," but despite the manpower disparity, Wei was unable to make any real gains in either Cao Zhen's or Cao Shuang's campaigns against Shu-Han. The latter featured an army that massively outnumbered Shu-Han as well. The terrain was treacherous enough to make it difficult.
Even the final push against Shu, which did result in Shu-Han's capitulation, wasn't a guaranteed success. Wei had some supply problems and although they were mostly successful, they ran into spots of resistance. Zhong Hui was unable to successfully budge Jiang Wei. Had Liu Shan indeed fled to the South of his territory from Chengdu, the barbarians there might have revolted against his rule, but on the other hand, Wei would have struggled with keeping up supplies. Jiang Wei was still at large and could have potentially been hazardous to a sustained campaign by Wei. Wu was a factor as well. They were eying Yizhou seeking to fill whatever power vacuum might arise. Shu-Han wasn't at the limits of its strength when it surrendered, but Deng Ai approaching Chengdu was a psychological blow.
So therefore, they needed a general capable of using the terrain to their own advantage, and Deng Ai was the first one to effectively do that. Had he appeared in Wei's ranks during Zhuge Liang's time, what do you think would have happened? Would he have executed one large expedition and crushed Zhuge Liang?