Skill can make up for a poor tire choice but a poor tire choice remains a poor tire choice.....I don't think there is any reasonable way to introduce skill and experience into a tire rating system.
I certainly agree that dual sports face a level of compromises with tires (and everything else for that matter!) that pure street or dirt bikes don't have to deal with......or at least not to anywhere near the same degree.
Yet we introduce skill as a component of virtually every dual sport rally....the platform where our motorcycles and skills are put to the test. I normally run 6-8 "Dual Sport" Rallies a year (2018 was bad year where I did only 2. one in March and one in December). Irrespective, every one has/had a component of skill in the tracks or groups that each participant follows or joins and it ain't about tires.
My most recent rally was the annual Polar Bear Rally (January 4-6) where the 150+ riders were categorized A, B, C or D. I'm attaching a link below to Adventure Rider where you can see the category definitions. There's nothing about what tires one's riding in there.
So, kind of where my thinking is going is, if you take those four categories of skill (A-D), then create categories of dual sport trail surface types, then you could plug in the tire categories (green circle-double black diamond, if you wanted to use those) by skill level in a matrix format...i.e. the basic X and Y axis analysis. Personally, I think it would be better to use actual tire models than color/shapes, but either way the result would be something along the lines of a more experienced rider having a broader selection of tires (necessary for broader pavement use consideration) and a lesser experienced rider having a lesser selection (they're just going to have to use more aggressive tires until their skills improve).
Personally, I think this actually tracks the old adage that I attribute to you that one never gets stuck on the road. Essentially, the matrix approach kind of paraphrases that by saying that a rider should get the most aggressive tire relative to their trail plans that they can reasonably put up with on pavement.
Polar Bear Rally Thread
Hey Samuel, going back to your post, what would your view be of a matrix that on the Y axis (vertical) had four skill levels A-B, one of which you could identify with, and on the X axis (horizontal) had several trail surfaces (minimally hard, soft, intermediate; this is how we used to look at motocross tires). Then the axis' connection was either a symbol of tire tire type or a list of actual brands and models? I mean, at the end of the day, I'm going to get by. The test of a good system is if it responds to all skill levels and, in particular, the more inexperience trying to get into Dual Sport or improve their skill levels.