Roughly one in five Koreans have surname "Kim".
Upward of 40% Vietnamese have surname "Nguyen".
"Li" is quite popular in China.
Specifying "Asian last name" in this context is quite apt.
The odd thing is one of the guys has the first name Chang, and the other guy has the last name Chang.
The odd thing is one of the guys has the first name Chang, and the other guy has the last name Chang.