Complex sentence: Since Lung Kong is restricted to only four families names, people with names other than Liu, Guan, Zhang, Zhao had to form their own family association to take care of each other, and help other Chinese immigrants.
Split into simpler sentences: Since Lung Kong is restricted to only four families names. People with names other than Liu, Guan, Zhang, Zhao have to form their own family association to take care of each other, and help other Chinese immigrants.