An exciting and fun topic. I once saw a similar question posed about the archetypical diesel locomotive. In that one, they looked at the North American fleet, i.e., age, horsepower, number of wheels, manufacturer, etc. They managed to come up with one. If we used a similar methodology, it might be:
Course Type: Since 2/3 of courses are public, I think it must be public.
Course Age: I would have to look this one up, but I suspect the building booms of the 1980-90's would move the average age to somewhere post WWII. I just did some math and if I am correct (unlikely) it seems the average course age is about 27 years.
Site type: I am just guessing, but I believe the "Parkland course" would be the most dominant type.
Length: This could be measured with research, but I guess the maximum average yardage would still be just under 7,000K.
Par: Almost certainly 72.
Course Rating: Maybe low 70's?
Course Slope: I know the average is about 116.
Architect: I would have to look this one up, too. But, If Ross, Jones, and a few others have designed hundreds of courses, down to the struggling are amateur architects over the years that might have designed only a few, I will say the archetype course should have been designed by an architect who is typical.....maybe having designed 50-60, mostly public golf courses. If we include average budgets, it might be someone like Geoff Cornish, or maybe the legion of us who made a living in the 80s-90s. Perhaps a guy like Dick Phelps.
So, the archetypical course should be:
Public (average green fee around $40)
Built about 1997 (although this does seem too new to me....)
Parkland
Par 72
Rating: 70?
Slope Rating: About 116
Back tee length is about 6,900 yards.
Architect: ??
Does anyone know a candidate that fits these descriptions?