How a Westerner is learning to draw/paint a Chinese face

I have been in China for a few months now. I have been spending much of my time observing faces, facial features, facial expressions in order to draw and paint what I am seeing. It seems that it is hard for a Westerner to draw a Chinese face accurately and it is hard for a Chinese person to draw a Western face accurately.  Last year I visited the new Martin Luther King, Jr. Memorial in Washington, DC, which was created by Chinese sculptor, Lei Yixin. There has been some controversy surrounding the accuracy of the inscriptions on the Memorial, and the fact that a Chinese artist was chosen to do the work. Others have criticized the sculpture saying that MLK's facial features look Chinese and that his clothing has a Maoist style.

I was at a popular Chinese tourist spot last month, Honzhou Lake and some local artists were drawing Chinese brush paint portraits. I had my portrait done and I think the artist made me look a little Chinese! A few weeks later, in my painting class, my instructor, Mr. Chen, told me that my underpainting of the Shanghainese model made her look too Mongolian. Honestly, this Westerner can not tell the subtle differences between someone from Shanghai and someone from Mongolia.  At the risk of being a "Paula Deen," I also can not tell many of the Aussies from the Brits the Germans or the Americans here (or anywhere).  Anyway, I am a minority in a foreign country and observing the similarities and differences is what is informing my art practice. So... I made adjustments to the underpainting of the model. When the painting was finished, the first Chinese person to see it, commented that it looked like a Westerner painted it! It's baffling to me that it is so difficult for each culture to capture the other accurately in a portrait. So much conditioning! Maybe much of what is expressed has to do with how we actually see ourselves and each other. 

Unlike observing faces in the States, the Chinese faces I have seen, basically have the same nose, eyes and mouth, just rearranged a little uniquely in each person. Standing in a crowded subway car, watching the hundreds of faces come and go - all with similar features! It's like observing snowflakes or roses: they all seem the same from a certain distance, but after some observation, each is unique in it's own special way. How can a creator make so many varieties of just a few features?

I thought it would help me in my drawing to make a board in which I just rearranged the individual facial features to create unique characters, but I am still pondering that.