Why is Emperor Wu's mother surnamed Wang and his uncle surnamed Tian?

Wang Yi is the birth mother of Emperor Wu of the Han Dynasty. She is a very important woman who influenced Emperor Wu of Han Dynasty to become a prince. Wang Miao's mother is Zanger. Zanger was once an eighteen-route vassal of Xiang Yu. She once sealed a Yan Zang tea, which belonged to the 18 th Route Governors of Wang Zhiyi. Later he surrendered to the Han Dynasty. In the fifth year of Han Dynasty, Zangcha rebelled and was put down by Liu Bang, so Zangcha's family died. Zanger was Zangcha's granddaughter, a Rebecca. Her family has a glorious past. Later, when he died, Zanger remarried, married a field and gave birth to two sons, Tian Fen and Tian Sheng. In this way, Zanger got married twice and gave birth to five children. Later, Wang Yi married a man named Jin and gave birth to a daughter.