I really don't remember ever using that AI in BG1 or 2.
I always just fully controlled my party, cast the spells I wanted when I wanted, controlled my positioning, etc. Maybe I'm one of the few who played it that way?
I can see what people are saying about not having that sort of AI in PoE, but I haven't ran into any issues yet. I play as a Ranger with a bow, a bear companion (tank), and other characters in my party. The main aspects of combat thus far have been choosing which enemies to attack, controlling the battlefield via positioning, and activating the odd skill or spell here or there. It's actually a nice balance of managing every move and letting the battle play out a bit.
Don't take my word for it, though. Just play the game and you will see. It's a fun little combat system and I feel right at home with the game, as if I'm playing BG3 in HD.