I used to run a 24 hour restaurant... staff of 18. Upstaffed to 20 for really busy times (holidays).
Also, restaurant is a bad example. There you want to spend 1/3 on food, 1/3 on operating and 1/3 on payroll. In the NHL the Players themselves are part of your food and operating (the product).
Talk about tiny
if you were open 24 hrs. That's 3 shifts. 3 waitress, 2 cooks, 1 dishwasher/mop guy. for each shift. Your staff would have to work 6 days a week. You would have to close 1 day a week. Nobody could ever call in sick or go on vacation. and there is no bar guy and nobody incharge.
We couldn't even run a takeout place with 18 think there were close to 30 albeit 10 were probably part timers.
About your 1/3, 1/3, 1/3 claim, times must have changed since the 70's. When I was a kid I worked in the fast food biz. Even there the situation was different for each type of restaurant.
Unfortunately I can't recall the labour costs, all I can remember were the food costs we had to maintain to meet our bonuses. In the chicken business it was 47.5 % (takeout). In the pizza business it was 10%.
The average Swiss Chalet has a staff of about 50. I wasn't referencing the corner greasy spoon where Gus and Sophia do everything, from swatting cockroaches to doing the books.