Reasons:
1. In Kung Fu Panda 3 it is stated "Emperor Hawk", meaning that the Emperial species is canonically the hawk and not tge peafowl.
2. There was never been a Chinese Emperor with the surname "Shen"
3. Gongmen City is NOT the Capital. There has never historically a Chinese Capital located along the southern coastline, which is where Gongmen is.