I guess I always just assumed (without much questioning) that it was a term that likely meant something else or was more specific that later was used as a name and became a broader term over time. Like “guy” was a literal name for a place or generally male specific tool or some shit like that.
Swann was similar to that and also Gunn (both words first) which is the Scottish clan that Swann originated from. For some reason I never thought much about my first name and where it originated. My curiosity was always focused on tracing last names through the generations.