Nowadays, people's surnames are all the same, such as "Qiansun Zhaoli", which are all people's surnames, but in ancient times, surnames were separated, not just one. Just like Ying Zheng, it can also be called "Zhao Zheng". Because "Won" is the surname of Qin Shihuang and "Zhao" is his surname. Generally speaking, surnames represent status classes, while surnames are used to avoid intermarriage. So if we look at people's past surnames according to their current surnames, it is wrong.
However, in addition to surnames, Qin Shihuang also named his two sons at will. Even if many of us name our children now, we have to look at many things, such as birthdays, the meaning of names and so on. However, Qin Shihuang's two sons, the eldest son, were named Fu Su because his mother liked the song "Mountain with Fu Su" very much, so Qin Shihuang gave his son the name of this song. But from this point of view, the name "Vulgar" is actually very meaningful and full of ancient customs. The second son's name is Hu Hai. He was named because Hu Hai's mother was in the semi-finals of the conference, and he was born in Shihai, so he was called Hu Hai, which was a bit careless.
Qin Shihuang was actually a genius emperor. Although he casually named his son, in fact, his son took his surname, but his full name was not written in history. Later, for the convenience of management, the surnames are unified now, which is much simpler and clearer than before.