If you look at the map linked above, you will notice dozens of villages throughout the Tribe’s territory. Before European invasion, each village had its own leadership. People married outside of their village for many reasons, including the maintenance of ceremony, economy, peace, and healthy genetic practice (e.g. not marrying your sibling or first cousin). As a result, every Tribal Citizen has multiple tribal ethnicities from neighboring indigenous regional groups, such as Tataviam, Chumash, Vanyume, Serrano, and Pipimaram.
Remember: There was no such thing as racial blood purity standards prior to European invasion.