Is “The cause of death and killer of Wu Lan.” true?

The novel describes that in the Battle of Xie Valley, Wu Lan encountered Cao Cao's son Cao Zhang, and after a few exchanges, Cao Zhang stabbed Wu Lan off his horse with a ji (halberd) (Romance of the Three Kingdoms, Chapter 72: "Cao Zhang happened to meet Wu Lan; the two fought, and in less than a few rounds, Cao Zhang stabbed Wu Lan off his horse with a ji."). In official history, when Wu Lan retreated to Hanzhong after the Battle of Xiabian, he was beheaded by Qiang Duan of the Yinping Di tribe, not killed by Cao Zhang (Records of the Three Kingdoms, Book of Wei, Annals of Emperor Wu: "In the third month, Zhang Fei and Ma Chao fled to Hanzhong, and Qiang Duan of Yinping Di beheaded Wu Lan and sent his head.").