Well the idea is, an individual will turn in the same performance regardless, though their rankings may be different if they attend a high performing school like Ruse, they will still be the same person performing at the same level. Average ranks at Ruse vs average ranks at a bad school is too general to comment on-the candidature will vary each year. So a school does not receive scaling, it is the performance of your peers which will affect you. You can of course immunise yourself by ranking first in a subject.
Moral of the story: Anyone can can get any mark at any school. It is the individual which determines the marks, not the school and how good/bad it may have performed in the past.