They dont scale "equally" as such, because they look at how the candidature perform in the common paper and do things from there... im sure laz can fill you in on how it works
Adv. english is quite difficult.. the texts in std are alot simpler, and your not demanded so much in terms of 'perfect' essays and stuff
saying that, however, id recommend doing adv english, and just working alot harder.. maybe consider getting a tutor... doing adv will pay off in the long run