At the dealership level, larger Japanese brand, metro area dealer. We had two bays dedicated to "express" service, i.e. LOF, rotations, top fluids, wiper blades, quick inspection, test battery, etc. with a 30 min guarantee. Usually we had 2 hourly guys per bay, but sometimes would have 3 guys covering the two bays, and always at least one guy to greet, write an RO, discuss inspection with customer, up sell, etc. usually 2 guys did this, sometimes 4 or 5 when we were swapped.
Normal 11 hour day, we'd see ~50 cars, on Saturdays we were only open 8 hours, and would see at least 50, sometimes 70+ if we had a promo going, I think the most we did in a day was around 115, but that was pretty rare, and horrible. Corporate's stated goal to the techs (not advertised) was 15 min or less per LOF/Rotation, the service manager wanted it done in 12 min. They didn't always make that, and there's always up sells, and often major repairs or wear items to replace, customers that vanish, techs having a bad day, etc. We tried to get those customers with larger repairs into the "main shop" right away, but when the flat rate guys are treading water to keep up, it's nice to have a deal with Enterprise, and put the customer in a car for a day. Even with free loaner cars, and Enterprise, we still had to schedule come backs about half the time.
Complimentary car wash was not included in the 30 min guarantee, first nice day in the Spring, everyone wanted their car washed, 5 min wash cycle, and 10 cars in line for a wash, customers were told upfront, "we'll gladly wash your car, but you may be here a while." Most still waited.
Techs were in pairs, so one did the LOF and topped fluids, while the other did the inspection, rotation, and other stuff if needed. Mostly so they were held accountable when someone stripped the oil drain plug, or forgot to tighten a lug nut, they couldn't say, "the other guy did it."
So 25-30 per tech on an average day is about right.