Guangzhou isn't that bad, have you been there recently?
I learned to ride in Hanoi, I spent a year in various parts of vietnam and was very comfortable in SEA traffic on a bike.
None of that prepared me for the chaos of HCMC. People going the wrong way, people visibly drunk on bikes, randomly finding yourself surrounded by semis on cracked and broken pavement, you and 20 other bikes making offroad detours to get around cars.