Is “In the novel, after Zhuge Liang's death, Jiang Wan succeeded as Prime Minister, but in official history, Jiang Wan never held the position of Prime Minister.” true?

The novel writes that after Zhuge Liang's death, the Later Ruler "followed Kongming's last words and appointed Jiang Wan as Prime Minister, Grand General, and Supervisor of Secretariat." According to Records of the Three Kingdoms, Jiang Wan initially "became Chief Clerk, overseeing state affairs," then "was promoted to Grand General," and later "was promoted to Grand Marshal," but never served as Prime Minister. The novel partially rewrites his official titles.