I got something for you that's called D&D rules + reasonable cutom rules.
1) Remove the highground and backstab advantages and convert them into +2 to attack roll.
This way you can increase your basic %to hit by 10% (average) if you wish.
Of course it require a rework of jump/disengage to become a meaningfull choice.
2) Use the advantage mechanics of D&D.
This way the game is opened to MANY strategies, possibilities, synergies between characters.
You can have an average of +25% on your attack rolls.
3) Then you can also use bless, the usefull spells of clerics and paladins to add another +5-+20%.
(I know, a party of 4 is very limited and we don't have many choices to play with classes we enjoy a little bit less)
10+25+(5-20, let's say 10) = a possible average of +45%
Isn't that enough to you ?
I guess it is.
That's the only solution to increase our control on the %to hit and our tactical choices without creating even greater difficulty problems.
Unfortunately, that would be :
a) not 45% but only 10% improvement ( we all already use advantages, so those +25% are already present and would not additionally help with misses ; and we already can use Bless but it force our character choice )
b) even those 10% ( due to modified highground rules ) would make game easier by same amount, and may require rebalancing
c) would require significant rework of current BG3 mechanics
*EDIT* Another thing about this is that with your true-DnD advantage proposal, getting advantage would be much more rare than now since currently high ground is main source of advantage ( I know that it is exactly what is an issue for DnD crowd, but ...). So on every fight where I before had advantage due to high ground I will now miss 15% MORE ( gained +10% due to high ground, lost -25% due to no advantage )
I get that people who would like "true DnD rules" are prone to suggest removing non-DnD mechanics ( like "remove height advantage"), and while this is maybe only version of removing height advantage so far that would not make me strongly against, it does not address directly goal of "reduce misses without making game easier or disbalanced".
