We have an older cat who almost never leaves the house. Our house is fenced but open, if you go to the kitchen during rain you'll get wet. So occasionally other cats turn up in our living room.
Usually they growl at each other and then the other cat leaves. This repeats for a few nights and then they don't come any more. The other day there was screaming and I found pee on the kitchen floor, although I didn't witness how it got there.
Now I wonder, when I see them growling at each other, should I rather clap my hands and chase the other cat away or let them negotiate on their own? Is there a risk that our cat might lose her territory and feel forced to move out?