I think this entirely depends on if the people involved in the comparison are using the same basis of measurement. If everyone agrees on what is being measured

I think this entirely depends on if the people involved in the comparison are using the same basis of measurement. If everyone agrees on what is being measured and how, then it should be easy to then do the measurements to get results. (who is best) If the people involved in the comparison don't agree to a basis of measurement, then it's an exercise in futility and nothing more than an exchange of opinions.