The enemy attacking your party head-on would be more realistic? No, absolutely not. I just like the way the foes teleporting and jumping just to find a good position. The key point of the combat in BG3 is you need to find a better position than your enemies, as well as using different spell just to deal with the enemies which is much more dangerous to you party, with higher priority. This is also the key point of the turn-based game. If the enemy always attacking the warrior and ignore your wizard with only 1 HP - this is not what you call realistic, this is stupid.
I don't really agree with this analysis. How else do you fight someone but head on, unless it is an ambush? Once the element of surprise is over and you have launched your attack from behind or the side, you can guarantee your foe, provided they are still standing, will the be facing you head on.
Not that bringing reality into a fantasy game holds much weight but I'd hazard a guess that once a fight starts (these aren't battles, given the small number of people involved in the fighting), the last thing you'd want to do is show your back to an enemy in an attempt to get away and find a 'good position'. There is too much emphasis on positioning and the environment in this game.