Do Singaporeans look Vietnamese?

No offence but since they are south east asians wondering whether they look alike or rather maybe i should add cambodian chinese to the topic bcos all dark and tanned and most don't look koraen or japanese. And Singaporeans and Vietnamese, I am just wondering why most of the guys in these contries enjoy wearing polyester boardshorts most of the time. And in Cambodia and Philiipenes how come there are higher chance of kids getting swallowed by pythons rather than japan and korea.