I have read somewhere that Genghis Khan has a bunch of legendary generals whom he call "Dogs of Wars" and they consisted of Subothai, Jebe and Guo Kan. I am just interest to know whether JY could have modeled Guo Jing from Guo Kan as Guo Jing was one of Genghis' able general before he took arms for the Hans. Apparently, Guo Kan was a Han Chinese who served with Genghis up to Kublai and was instrumental in sacking of Fancheng and XiangYang. And the irony of it is that instead of saving XiangYang, he whacked it!