Climate of Han immigrants in Southeast Asia

Yes, because of the rule of Yuan and Qing Dynasty, Han people moved to Southeast Asian countries. Now the Han nationality in Chinese mainland is descended from Mongolian and Manchu, so the race and folk customs there are more like the ancient Han nationality. However, the Han people in the Tang and Song Dynasties were also mixed-race. Let's say Li Shimin. Are there any Han people with a surname of Dugu? He even said that he was actually a Xianbei person.