Pat,
I think there should be at least one immutable feature that describes a hole type, along with a couple others that can be interchangeable. For instance, both greensites on the two holes I mentioned don't stand alone, they back back into hillsides. Both of their fronting slopes are very steep making for an abrupt transition from the fairway, and both greensites are very high above the fairway. I think they fit the volcano mold.
Defining holes reminds me of a '79 trip to Fla I took with my then wife-to-be in our two-door, black and white, 1954 Chevy BelAir. We drove on back country roads (shades of Robert Mitchum) all the way there and at just about every place we stopped someone would come up and say: "Ya know, I used to have a car just like that. 'Course, she had four doors, blue paint, and she was a Buick, but dang, she was just like this one".