some of them even throwing source spell around
This is the problem. Not Wits.
I had a level 3 enemy cast Mortal Blow on me.
Larian clearly stated that enemies skills and abilities weren't balanced yet around the AI 2.0 and that the vast majority of them are going to see their spell list gutted because of it.
Also, the fact that enemies have a hella lot more ranged on their attacks than we do is what make them able to actually kill people so fast. Because they don't even have to move to start attacking. It's also why melee enemies feel so weak.
