Then you have zero to no idea about Christian and Vietnamese culture. The Vietnamese worship their ancestors while Christian does not allow to workship ancestors, many Vietnamese refuse to become Christian for that reason. Many Viet practice Catholic and also worship their ancestors they combine the two.
That is only one of the examples of conflicts between culture, religion, and identity.
The case of Korean were nomad people and had weak religious. That can explain the fast rate adoption of Christianity.
The Japanese have a strong Shinto religion that can explain low Christian adoption.
The Japanese still using Kanji based on Chinese characters, because Chinese was not a threat to their identity.
Vietnamese abandoned Han-Viet to adopt Latin based because they have always wanted a separate identity.
English is treated as the second linguist in Vietnam even though there are not many English live in Vietnam because they don't see English as a threat but economic opportunities. This contrary to how French was perceived during Indo-China war.
here is my intake, Most Christian has no problem with Buddhists, in fact of all the non-Abrahamic religions around the world. I say Buddhists are the most tolerable here why.
1)Buddhism is more of a cultural philosophy/enlightenment & not a religion that deals with a God deity. ( my definition of Buddhism is atheist)
2)Buddhism's definition of worshipping ancestors isn't the same as the definition of Abrahamic worship of God. ( Buddhist doesn't treat your great father as the creator of the universe)
3)budda's concept of God is that God is everywhere in the water, trees, animals. ( same kami beliefs like Japanese).
For Christians, Christians call it the '' holy spirit of God'' holy spirit can move the waters. holds everything on its place & it's everywhere.