More anecdote from another ex-waiter: #2 was the complete opposite at the one place I ever worked, serving 8 people was much harder than 2.

The variation in sentiment might have to do with that my restaurant didn't have runners, and it was an Indian restaurant. We did food delivery ourselves, and customers needed at least two things to come for dinner (an entrée, and naan), making it stressful because once a table got to 6+ people, you had to run two massive trays of food from the kitchen to the floor, as quickly as possible.