About ten years ago I wrote a spreadsheet to determine, or allocate, a "difficulty factor" to a course design. It factored longer targets harder than close ones of course, but not on a linear basis, it included a factor for wind on that lane, and it had the equivalent of what you are calling a wobble factor, Brian. Effectively it took a target at say 40 yards in a given wind, and allocated a reduced percentage chance of knocking it over if it was a kneeler or a stander instead of a freestyle.
Feedback comparing predicted "difficulty" with real life courses showed that your wobble factors are close to what I used eventually. I ended up with a kneeler factor of 1.5 and a standing factor of 2.25.
HTH
Rich
