Qingdao Liuting(TAO) and Lanzhou Zhongchuan (LHW) both seem a bit small scalewise.
Both are scale 2 right now.
Qingdao has over 20 million passengers per year irl and has 787s, A330s, and 777s.
Lanzhou has over 10 million passengers a year irl, although admittedly the largest planes it sees are A321s and 737 MAX 8s.
I think Lanzhou could be a scale 3 based on pax volume alone, although i understand if it remains a scale 2 considering it doesn't regularly see widebodies.
Qingdao could be a scale 5 or above, considering Changsha(CSX) has a similar number of pax per year and is a scale 6
(passenger numbers are from
https://en.wikipedia.org/wiki/List_of_the_busiest_airports_in_China, and planes are from flightrader24)
Edit: added IATA codes, fixed typos, clarified title