I really think that the problem with the difficulty of the game comes from the two VERY unbalanced system they use.
D&D is balanced to be D&D. Their homebrew are balanced to be powerfull. But those systems aren't balanced together at all.
Players has to find something in the middle but most D&D things are not powerfull enough while Larian's homebrew looks like "cheese".
How could they create a normal difficulty level arround "cheats" and arround "weak" features/spells/attacks/weapons at the same time ?
A better balance between those mechanics could probably solve many issues with the difficulty and increase our viable/creative solutions to deal with combats. The easiest way is to tone down their homebrew/items/mechanics first. THEN they'll be able to balance monsters.
Missing is something else and according to me, it comes from a bad understanding of the rules of advantage.
