Millions of descendants, all named by themselves. How did Zhu Yuanzhang set rules for future generations?

Zhu Yuanzhang's rule of naming children and grandchildren is to take Jin Muhuo, water and earth as one of the radicals, and then give later names according to the specific meaning. But there are many descendants of the royal family, but they can't share the same name, but this can't beat Zhu Yuanzhang. In this case, you can find those uncommon words to make up your own words. In this way, millions of descendants of Zhu Yuanzhang were all named in their own words. Zhu Yuanzhang's name is actually very marketable, probably because Zhu Yuanzhang himself didn't have a specific name since he was a child. Zhu Yuanzhang actually cares about names. First of all, when Zhu Yuanzhang named himself, there were still many meanings in it. At first, because of his low status, he only had a simple numerical name, called Zhu Baba. Later, when he grew up, he changed his name to Zhu Xingzong, meaning that he hoped his clan would prosper. After Zhu Yuanzhang participated in the peasant uprising, he considered the problem comprehensively. Knowing that he should pay more attention to his self-cultivation, he changed his name to Zhu Deyu. However, after he married Ma Xiuying, his thoughts changed again. He wanted to be a sharp weapon to destroy the yuan, so he got the name Zhu Yuanzhang. When he became king, he knew that he could no longer name his children and grandchildren with simple numbers, so after careful consideration, he named his children and grandchildren with five elements. The five elements are born together, endless and handed down from generation to generation. Zhu Yuanzhang decided to name them because of the moral inside. The first word must not be changed, so the second word is wooden as the radical. For example, Prince Zhu Biao and Prince Judy are beside the wooden characters used in the second word. If the son uses wood, then the grandson will all use fire. For example, Zhu Yunwen is the son of Prince Zhu Biao and Zhu Gaochi is the son of Prince Zhu Biao. Let's talk about their fourth generation, and the fourth generation all use local characters. For example, Zhu Gaochi's son is Zhu Zhanji. The fifth generation are all people next to gold, such as Zhu Qizhen and Zhu Qiyu. The sixth generation is water, such as Zhu Jianshen. As for the seventh generation, it has started again, and this cycle has been used.