Last year some of us weighed out yield from cooked butts for a couple of months.
They were different brands,sizes,some injected,some previusly frozen,all bone in.
Typically cooked to 195�and pulled very lean.
Over that period ,my yield was 46%.
Personally ,I'd cook the four butts and a few hotdogs for kids.
If you think they are eaters,a fifth butt is cheap insurance.
I'd have a minimum of 1/3 lb cooked meat per person.
36lbs raw, should yield about 50+ servings of 1/3 lb.
My team member Craig caters and he'd probably have a better answer.
One unexpected result we had last summer,during the lo carb diet craze, threw all guesstimates out the window.
The team cooked for a group from 8 to 80.
Some current athletes,spouses,kids.
We were serving ribs,pork,burgers,wings for meats.
Beans,slaw,buns,and a sweet dessert.
They skipped the buns,beans,slaw,dessert, and ate mostly meats.
Go figure.