China Southern are offering fairly cheaper full service flights to Bangkok, Chiang Mai, Thailand or Yangon, Myanmar for $762. These flights include bags, meals and seats. Dates are March - August depending on the route. Short stopover in Guangzhou.
So yes there are some dates where Air Asia is cheaper however there will be more stopovers (Australia and Malaysia) and you'll be paying extra for bags/meals/seats.
Find the cheap dates on Google Flights then put them in Skyscanner or whatever site.
Bangkok $762 - Google Flights - Skyscanner which was mentioned here last month.
Chiang Mai $762 - Google Flights - Skyscanner
Yangon $762 - Google Flights - Skyscanner