You can look at a thicker English dictionary. There is usually a list of common European and American names at the back, which indicates which ones are surnames, which are first names, and which ones can be both. There are not many people who can be combined, that is, they have different names or surnames. Many European and American names are derived from Christian names, and many names appear in the Bible. Most parents just look for a reason when naming their children. This is like the Chinese naming their children. They hope their children will be like Confucius and call them Zhongni. If they hope their children will be like Emperor Taizong of the Tang Dynasty, they will name them Shimin. (Very few people do this in China. There is no such custom. ). The Chinese choose names because every Chinese syllable (that is, a word) has a real meaning. The two-character names are actually like a new word invented by the parents themselves. Although it is not in the dictionary, people seem to understand the meaning of the name, and it has become something personalized for each person.
How many surnames there are depends on when the surname became widely used. China has had surnames for a long time. The population was small at that time, so there are not many surnames now. There are only more than 500 surnames in a hundred families. Due to the smaller population of North Korea, which is influenced by China, there are now only more than 100 surnames, and there are fewer and fewer. Many lower-class people in Japan were not allowed to have surnames until the Meiji Era. You can think about how many surnames there would be if you had to decide on your own family name at that time. It is said that there are more than 120,000 surnames in Japan. Arab countries do not have surnames and use consecutive names. I don’t even know the specifics, but the names are connected from one’s own name to the father’s name and then from the male’s side to the ancestors.
You should have the impression that European and American people should have a lot of surnames, because if you only mention the surname, there are not many chances of having the same name. Not so with China. I think this is also related to the era when the surname was officially used and the number of households at that time. Of course, it is also related to subsequent language changes and other factors. There is no exact number, but various countries will have approximate statistics. For example, the UK has more surnames (their origins are somewhat mixed) than China, while Spain seems to have fewer surnames.
My ideal most scientific name structure should include three parts:
Original name, mother’s name, and father’s name. As for things involving several generations or more, you can follow the clues to find out. Regarding a person's parentage, the most important people are his parents. These are two relationships that a person must have. As for the ancients who lived N generations ago, the higher the number, the more numerous they were. Which one did they use as the symbol of their home? It’s hard to say, it’s better than this.