I generally agree with most of this thread. I too think the phase spiders and spiderlings are strangely implemented, and that the spider fight overall focuses too much on verticality rather than genuine, monster-accurate strategy. Part of me isn't too bothered, though, because I believe it's highly possible that Larian just haven't finished the 'phase' ability and are using misty-step as a placeholder. The spider fights aren't really linked to the main quest and to me it seems like the most left-field bonus content of the entire EA, so it makes sense to me that they haven't finished implementing the full mechanics of that battle.
However, I have no real problem with the intellect devourers at the beginning of the game. It makes sense to me that Us doesn't insta-kill Tav and take over their body because Tav is host to a highly unique mind-flayer tadpole that needs to be protected. I also have no problem with Us not being able to insta-kill the Commander, because I consider winning that battle to be an 'easter egg' of sort and not really an intended result of the tutorial section - the same section that, if you do manage to kill the Commander, has the Mindflayer turn on you and the party, including Us, who can then attack its Mindflayer master? So I take that whole section with a grain of salt.
I also have no problems with the intellect devourers on the beach. I saw people complain that the party of 1 or 2 including shadowheart at level 1, or 2 if you did manage to kill the Commander on the nautiloid, shouldn't be able to take on 3 intellect devourers. Sure, but I'm also going to assume that the intellect devourers on the nautiloid were newborns just like Us. Also, remember, they just fell thousands of feet from the sky in a fiery blaze after warring with githyanki *and* imps, the intellect devourers on the beach are wounded. They didn't have an 'Absolute' to magic them safely out of the sky because the Absolute doesn't care about them, so it's a wonder they survived at all. This is why it doesn't really bother me that Tav and Shadowheart can kill them at the beginning. It's not even that easy anyway, if you don't firebolt the tank and run up the ledge at the side for extra distance - they still can insta-kill the party if they manage to get in close. I don't consider this a 'nerf' because it makes sense narratively.
Apart from this, I would definitely like to see some more battle-instances that are designed around strategy and tactics rather than verticality and ranged attacks. Putting a crossbow in the hands of all my weaker party members so they can run away from and whack the minotaurs/owlbear etc that just keep jumping around the battlefield instead of focusing on my damage-dealing tank is just weird. Feels like some of the battles are really well designed, and then others are sloppy, and I'm not even sure if that's down to the AI or the enemy's stats/abilities.
