Advertising these as basic salaries gives little insight into the actual contract. In my experience the advertised rates will be based on so many block hours, duty pay, away from base allowance. etc. Or not.
Tax in china is high. If CargoLux do not pay your china tax, then take-home will be half what you get gross. Google china tax rates.
45% on 80,001RMB and above.
The elephant in the room is ability to pass AND maintain the CAAC medical.
Good luck with this, unless you are a current astronaut.