You'll find it very hard in Vietnam to have a decent standard of living and pay the school fees for 2 kids, on an A320 captain salary, at any of the 3 main airlines. I did it for the first seven years I was here, during which time the school fees have nearly doubled, with no pay rise from the company. I finally yielded to the inevitable last year and sent the family home, and went onto a part time commuting contract.
Here's the fee page for the main British school in Ho Chi Minh, you're looking at near $50,000 worth of fees per annum for the two kids, once your little one starts.
https://img.nordangliaeducation.com/...-2018-2019.pdf