Indeed. Ranking in the internal examinations, is important, however the INTERNAL marks are not. The rank indicates which external marks you will get to replace your Internal marks. So Say John is rank 1, Tom is rank 2, and Sally is rank 3 in Modern History. In the exam, Sally gets the top mark(95), John gets the second best (93) and Tom gets third best (90).
Because John was ranked first, for his internal mark, he will get Sally(the person who came first in the external exams) mark. So he keeps his external mark (93) and then gets 95 as his internal mark, leaving him with an average of 94. Sally will get her external mark (95), but her internal mark won't be 95, it'll be scaled down using the stupid UAC formula, to give her her mark. Heh. But it'll be close to 92 or so, as she finished rank 3 over the year...and the top 3 people did well in the external exams.
Get it?