Is “After Yuan Shang fled to Liaodong in defeat, he secretly plotted to kill Gongsun Kang and seize his land, but was instead ambushed and executed by Gongsun Kang.” true?

Chen Shou's "Records of the Three Kingdoms" only records that Gongsun Kang "lured and beheaded them." The vivid details in the novel, such as Yuan Shang's secret plot to seize territory and his request for a mat being refused, actually adopt the content from Pei Songzhi's annotation citing the "Dianlue," which is not explicitly recorded in the main text. The original text states, "Kang then beheaded Shang, Xi, and Supuwan, and sent their heads." ("Records of the Three Kingdoms, Book of Wei, Annals of Emperor Wu")