Sima Yi then ordered Fei Yao and Dai Ling to protect Shanggui County (上邽縣; in present-day Tianshui, Gansu) with 4,000 elite troops and set out with the rest of his men westward to relieve the mountainous battlefield. Zhang He wanted to take a detachment and station it at Yong and Mei counties, but Sima Yi reasoned: "If the vanguard is able to face the enemy alone, your words are right; but should they not be able to do so, the dividing of the forces into vanguard and rear would be unwise; in this manner the Three Armies of Chu were captured by Qing Bu."