Okay, I'm going to use the same scenario where Person A has the 92% assessment mark but received 80% HSC mark and person B gets 84% assessment mark but 94% HSC mark. Will person B be given the 80% HSC mark of Person A or will he retain his 94% HSC mark so that both Person A and Person B receive the 94% HSC mark?
If Person B loses his HSC mark then that is extremely unfair.
In your scenario Person A gets 94 as their moderated assessment mark and 80 for their exam so a final HSC of (94+80)/2=87
Person B will get 94 for their exam mark and a mark about 8 marks lower than Person A so a moderated exam mark of 86 giving a final HSC of (86+94)/2=90
In the final wash-up both benefit by the strength of their best performance but are pulled down by their weaker performance in 50% of the final mark. So Person B's great exam mark has benefitted both of them - as Person B keeps that exam mark and Person A who would have strenghts in areas other than exams, or who hasn't put in a lot of effort at the end, has been rewarded for consistency throughout the year but been pulled down by something - poor exam skills, poor exam preparation etc. If it was because of illness or other factors that would lead to a misadventure then they would be getting 94 for both.