In MANY ways i have to agree with the OP. I felt this the first time with the spider lair at first. i personally did this in 2 parts because i came back after going to other games and waiting for patches. After having come back i realize that its the AI itself. it plays a bit 'unrealistic' (i know i know its a game and also a fantasy one but hear me out to help fix this and make this a wonderful game).
After having come back to the game i remembered this area 'slightly' after going down the well in that there were a lot of spiders so i never finished my first time playing (i assumed i was too low level).
This time around i was LV capped at 4. Unless you know that the Matriarch will unleash all these eggs on you in this encounter, the moment they spot you; its pretty clear that you should stealth this and fire bomb the eggs before alerting the actual spiders patrolling or they will all teleport to you and others; thus wreaking non stop poison dmg. THUS DEFEATING THE PURPOSE OF PLAYING THE GAME VS RELOADING ALL THE TIME. But i reloaded about 4x to see how i could only get them to target the barbarian who is my front line.
Thus in your beefiest barb (trying out barb). All the whilst you keep your party FAR FAR AWAY so that they only go for your beefy melee cuz well, ya want those folks in front and it pained me to figure out how without everything rushing past them to go for the lower hp characters. this meant many reloads cuz the game wanted to always go for my other characters even though only ONE was actually doing any dmg. Barb: Just burned yo community down! what ya got?! them: i see a wizard with my 6 int that is 100' away from you, clearly them. erm........ wut?
The AI in this game is VERY UNREALISTIC of enemies running straight through them for guess who? everyone with lower hp! WHY in the world would ANYTHING dash past a beefy guy with a double bladed axe that just killed all your children, neighbors, friends, firebombed your house to the ground; to hit that guy in the back literally doing nothing to avoid conflict (yes i tested mechanics and they meant nothing).
So i reloaded again, kept my party WAY WAY back instead of FAR FAR (yes i kept them back further cuz way way is a legit measurement) if i did not do this, EVERY thing will phase around and make your world unfun. (dont matter if he's the most threatening as they lop spider bits left and right). this other member has far less hp, so we as spiders with insect intelligence (6 for phase), will go for them instead. (cuz we can totally spot the weaker hp folks ofc!) Which is in my HONEST opinion, stupid. if i knew that there is very little challenge. if i DON'T, its nearly a death sentence unless of course once again; i KNOW THIS and use anti toxin on every party member before hand, buff to the max because i KNOW this fight. Forcing reloads?? Stop all that reload crap please.
This is all COMPLETLY against what DnD is about. Accomplishing things 'another way'. Which i love how you can do with dialogs now. Not everything has to be combat oriented. +1 on that at least.
This was another problem in DOS2 IMO. everything had this 'we have to teleport mojo' to EVERYTHING that IMO FORCED you to build different to counter it by taking TP (teleport) options for EVERY character. then it became more 'BALANCED'????' again; STUPID. FORCING ANY PLAYER INTO TAKING CERTAIN ABILITIES BECAUSE THE GAME ABUSES IT, IS VERY VERY BAD.
Also i think it's the fight itself having simply too many phase spiders. these things traditionally are difficult to begin with. I've played PNP for over 20+ years and i can honestly tell you i probably would never put a matriarch in there with so many offspring at even level 4, let alone the clusters if no one knew about them in the first place.
Fix your AI. If a living creature doesnt want to die, but fight, they are not going to provoke all the time to get to that lower hp guy or 'easier target'. that's not an easier target. its poor AI. i know i wouldnt run through a raging barbarian and 2 other folks forming a line to jump over them and get hit multiple times to get that 1 guy. that just makes 0 sense to me.
In the end does it make it harder? I can literally just rush in there and get an idea then use the magical reload right? not fun. Is the AI in this game as stupid as DOS2? yep.
You're doing great things here though Larian. just remember the roots of DnD. Customization. Choices matter. AI do not always have a box of rocks in thine head. Everything has self preservation sheesh. Be a better GM. i believe in you!
we shouldnt have to make perfect reloading choices or be forced to build a certain way. Thanks for reading :)