Here is some more info about small matches:
https://thegeneticgenealogist.com/20...I43BGnGk_xa1Xc
I remember spending quite a lot of time trying to find how my Bristow line might connect to a Bristow family who were early settlers in America, since I had quite a few small DNA matches descended from them. But then I found that my Dad also had several of their descendants as matches (about as many as I did), even though my Bristow line is on my Mum's side! I can imagine that if I didn't have access to anyone else's DNA matches, I would have kept on wasting time with that line of research for ages.