Before China, I think Hmong come from the Middle East. They may have been one of the lost tribes of Isarael. Below are several similarity between the two cultures.
Genesis 2:22 - a wife is a man's rib. All Hmong believe this.
Leviticus 12:2-5 - After a woman gave birth, she has to stay inside the house for 30 days.
Exodus 20:10 - Obey the sabbath day. Hmong in Laos, Thailand, and Vietnam still practice this. On the sabbath day, they don't do anything at all or go anywhere.
Numbers 5:27 - drink cursed water. Hmong now days still practice this. When they don't know who's at fault, they let the two drink cursed water.
Exodus 29:31-34 - When an animal is sacrificed, the family has to eat all the meat on that night. Do not save any for the next day. The left over meat has to be thrown away. Only Hmong Laos practice this.
Leviticus 7:22 - When they do a ritual, the family has to give the thigh of the animal to the priest, or now days, give it to the shaman.
Genesis 28:1 - A father has to bless his son when he's old or before he die.
Ezekiel 6 - God cursed the House of Israel so that they will scattered throughout the world, live high in the mountain, become other's slave, a third will be killed by famine and swords. This sounds like the Hmong people.
Prophets = Saub - Hmong skysoldiers still practice prophetcies.
Baal practice - Teev Nyuj Dab; Hmong still practice Baal, the sun god. Even though God hated it so much that He punished them for over 2000 years, yet, they still worship Baal. The true definition of Baal practice is to protect their crops, lives stocks, and family from harms by doing a ritual to the sun begining of the year before the sun comes up.
There are more similiarity then these but I just don't have time to look them up.