Is “Rescuing the Earl of the West and being a renowned minister of Zhou” true?
attested in history
The Records of the Grand Historian, 'Annals of Zhou,' records that Hong Yao and San Yisheng presented rare treasures and exotic animals to King Zhou of Shang, successfully rescuing the Earl of the West, Chang, who was imprisoned at Youli; the Investiture of the Gods completely follows the official historical record at this key plot point.
Hong Yao
Both official history and the novel list him as one of King Wen of Zhou's 'Four Friends,' and he once rescued King Wen at Youli; the novel largely follows historical facts.