Blood is blood. We are not all blood. Even if your sorta-uncle is there more than your real one. Genealogy is really pro blood connections. Adoptions are harder to adopt but can be done.
Here is a video and quick chart to help you define your connections.
When you get to larger trees you start to realize areas were small and so were populations so we may all be cousins especially once you’re in a SIG (Special Interest Group).