 When his plan was put up for discussion in the Shu imperial court, many officials objected to it and pointed out that the water-based route was too risky and not viable in the long term.The main reason was that if the Shu forces failed to capture Weixing and Shangyong commanderies, it would be much more difficult for them to retreat back to Shu along the Han River than if they were to retreat via a land-based route.The Shu emperor Liu Shan then sent Fei Yi and Jiang Wei to Hanzhong Commandery to meet Jiang Wan and present their case for rejecting Jiang Wan's plan.