Eliza: I would agree that your interpretation is about the only way to make sense of that part of the scene - although I would suggest that the servants may not even be aware of Benvolio's entrance, and that there is nothing in the text to suggest that they expect Benvolio to intervene in an impending fight. Further, in the copy I've just pulled off the shelf, the stage direction does not have Tybalt "enter" until Benvolio has already begun trying to separate the servants, which "delayed" entry is necessary in order for Tybalt to plausibly pretend that he is unaware of Benvolio's actual reason for having his sword drawn.