Simultaneous turns of enemies can cause a terrible mess.
First, it requires a much better AI, which is always a problem in games.
Secondly, it is much more difficult for the player to follow what the opponents are doing, which is important.
Various miss animations in the long run are unlikely to help either, because it's still a miss.
Maybe if they introduced a PoE system where to reduce the number
miss Obsidian introduced a graze mechanic which made you deal less damage instead of a miss.
Only this again can cause problems without increasing HP.
