I didn't see them state that but if the combat is somewhat set on hard difficulty I can understand some enemies being harder to fight. My issue as some others have stated is the chances to miss a hit. For example even using the environment around you, you can still miss. If you have the high ground and use a boulder to hit your enemy, it tells you that you have 88% chance to hit the enemy and when you do, it tell you that you missed. When it's the enemies turn, they knock you down from the high ground and take half the life of everyone. To me it seems the game is giving the bad guys the advantage.
Welcome to the statistics where having 80% chances to hit you still miss and having 20% chances you somehow hit ;P
Percentage only shows what they show - a POSSIBILITY to achieve something. There are always chances to miss and hit in both scenarios as natural 20 and 1 are very important part of the rules. It is annoying thow that even when I got mostly around 50% to 80%-90% chances to hit with my eldritch blast it DID missed very often. Call it unlucky, but it can happen and it is very much frustrating in real life pen and paper games. I've seen it goes both ways: awesome rolls and bad rolls several times in a row and I was avictim of this many, many times.
Thats why those other rules that Larian as a studio "homebrued" for they game work for me. That is pools of elental damage - they hurt enemies just by standing in them and falling dmg + pushing. Och, and thowing stuff is funny too
Protip - when in underdark use those flowers - they ARE usefull ^^
