The analogy given by the statement Cacciamanis are to the Montagues, is one that shows love between members of rival families.
The Rosemans and Cacciamanis are rival florists. However when Julie Roseman and Romeo Cacciamanis meet at a seminar they fall in love Despite reservations from Julie's sisters and Romeo's mother.
This is similar to the Montagues and Capulets, where Romeo and Juliet from the rival families fall in love.
So Cacciamanis are to the Montagues as the Rosemans are to the Capulets.
