Both are dependent on each other.
Example:
Person A came first in Business studies, but his marks were only just barely passing, and his exams were very easy. As such, that eprson may not have performed well in the HSC, and even though he is ranked first, he may not achieve such a high mark. - In this situation, it shows ranking doesn't necessarily always guarantee high marks.
Example:
Person B is ranked 40/50 in Business Studies. But his mark is quite good with 85/100 at school. As such from his school performance, it reflects his HSC performance and performs similarily well. He then end's up with a good HSC mark for Business studies, yet his rank was 40/50 which isn't so good.
What does this mean? Both ranking and marks are important. But in terms of which is most important, ranking is. The better you are ranked, the higher your moderated assessment mark will be. But as shown by the example, one cannot compensate the other, as various difficulties of in school examinations are very inconsistent which makes it hard to determine whether your performance is up to scratch.