Ok. I gave you and example of a legit D&D 5e game session fighting the first batch of enemies in the lair. I showed hoe they COULD use D&D 5e mechanics and it would still be a challenging fight, and I didn't even get to the boss fight. I showed how the party needed to use items to heal just to survive, making items important. I showed how cheeses are not needed.
The point is that if they actually balance the game appropriately you shouldn't have to use Larian homebrew rules. The spider lair would be really hard WITH proper rules and very challenging, and balanced.
I am reading the other posts, and my point remains. Larian said you have to use homebrew to make 5e works, but you don't. The game is MORE fun if you use 5e because it is balanced. Im playing it with 5e in tabletop. It is WAY more enjoyable, and the players can actually succeed without save scumming.
GM, I am going to say this as kindly as I can, that big long post you did of a TT battle representing the spider battle, literally, means nothing. Your biggest issue is trying to compare a TT game, to a video game. I mean you can keep posting these examples (because obviously by the length, you enjoy it), but I mean c'mon, you can't actually think that how it works on table top somehow says "see Larian, I was right, your encounters are all wrong! BUSTED!"
