There are probably thousands of cultures across the land sharing a vast majority of their ethics. I guarantee the vast majority of culture includes many altruistic ideas of coming together.

When two cultures with opposing ideas come together or collide, the victor’s culture often takes over. Sometimes integrating aspects of both.

Christianity is a great example of a religion that contains pieces of other religions before they splintered over time. Many religions share aspects because they’ve evolved with different groups into completely different systems of beliefs.