The height and backstab advantages are borderline ridiculous in this game and needs to be re-evaluated.
And real life eludes many too. Do I not gain an advantage if I am on higher ground than you? Do I not gain an advantage when I come up behind you without you knowing I am behind you then stab or hit you? Do you not have a disadvantage when trying to hit someone on high ground? Do you not have a disadvantage due to your limited line of sight?