Clarity on Exam Structure - NCARB please explain!!

I'd like to question the structure of the ARE exams. I have two exams remaining, including a PDD retake. And like many others, it's been a journey to even get 4 done. I have read a few articles, including NCARB "What score do you need to pass", in which it states that there are multiple exams per section, that vary in difficulty.

NCARB, can you please explain the reasoning behind this? I find it extremely unjust as each candidate has paid the same amount as the other for each exam while spending grueling hours studying, all to be given a more difficult version on an exam than the other. That does not create an even playing field and simply needs to be reviewed and changed. 

Good luck to everyone on the NCARB exams. Hopefully we get an answer.