I give up.
My hit rate is NEVER even half what the AIs is (usually 1/3rd) and virtually every battle I can count on 2-4 critical misses by me and 2-4 critical hits by the AI. Additionally the AIs range attacks have at least 50-100% more range then mine and hit twice as hard (on the rare occasions I do hit). With LOTS of save scumming and replaying most battles 3-10 times I was eventually able to get to 4th level and guess what ... it didn't matter in the slightest, characters are still 2-hit-wonders due to increased AI damage.
I've removed BG3 from my computer and will try again when the game is re-balanced and whatever horrid random number generator you're using has been replaced.