You didn't beat that fight legit or like a D&D game, you were just abusing the gimmicky larian feature like always.
So walking behind an enemy to attack it is abusing mechanics? The game isn't pure 5e and if you're gonna play it like it is, it won't go in your favor.
Also sure people get KO'd. Cleric can get them back up as a bonus action with heal. Let's say someone straight up dies. You should still have scrolls to revive them and keep going. Since the enemies tend to focus one person, it's not like the whole party is getting wiped, so the survivors can help that one guy.
I do agree there's a lot of cheese but you don't really have to play that way. Of course if you count backstab as cheese then it's pretty hard to avoid