IMHO, soup and salad are not appetizers, they are courses or part of 5 course meal. Shrimp Cocktail is an appetizer.
Our typical meal in the MDR on a cruise ship usually consists of an appetizer, cup of soup, salad followed by the main course and of course dessert. 69 cruises and we have never ordered an extra entree, on the Equinox last summer we were served 2 lobster tails at the same time, on that same cruise we ordered shrimp cocktail and the waiter brought 2 of those each also. On the Equinox about 6 weeks later we ordered lobster and were served one each but the waiter asked if we wanted another tail after finishing the first and we both declined. Both cruises sailed at about 82% of capacity.