I have tried with or without names; for me it would depend how close I am to the person I am telling the story to.

And depend if the 3rd party is known in positive/negative light. i.e. story that involves an ex to a current partner.

I think you might be over thinking this because for the most part it doesn't matter, however if you are developing a rule of thumb; if a story gives positive credit - name the person, if not positive, skip the name.