If I want to study Chinese, I will choose a Chinese native, but one who is a real teacher, not one with a BA in medicine, politics or history.
There are so many doormen, cooks, truck drivers and even jailbirds from English speaking countries in China.
What about their slang and idioms ? Americans are not an exception.
I met retired British teachers in China( with a BA in British literature ). It`s hard for them to get a job at their age, although they are real English teachers and not travellers.
Why a Chinese doctor, lawyer, cook or doorman cannot teach Chinese in the US, Canada, Australia and New Zealand ?