Just like Saymun Abadi said,Vietnamese thinks Hokkien(which they called người Phúc(Phước) Kiến)and Cantonese(người Quảng Đông) are Chinese.About both languages,Vietnamese says they are similar to Thai language,saying their languages are “the language of bird singing”(Tiếng của chim hót),though ironically-Hokkien Cantonese and Thai languages are somewhat simliar to Vietnamese.
Blue color circle(including Vietnam,Thailand,Guangdong,Fujian):
Vietnamese’s always thinking they are unique,different from other neighbor countries(because they fought against invasion from the north for thousand of years).
Not all languages are not influenced or shared similarity from other languages.Every cultures has been mixed or orgins as same as others.Look at English,it’s orgin a Gemanic languages, but mixing with Latin,French and Norse languages together to become language we speak today.