I put a rogue on the cliff where the witch teleports so they can backstab and crowd control her as soon as possible, and my third character stays at my lead character's side so they can distract the enemies spawning in the middle and some of those beetles (I think they were beetles) spawning at the edges of the area. I usually put my ranger on the highest cliff on the (I think?) eastern side of the room, the one adjecent to where the witch teleports once combat starts.
While she is locked into dialogue, you can freely move the remaining three party members around.
In that battle with the witch for example, your lead character has a lengthy conversation with her. But remember that there are tricks to get around that. Click to shrink.Yeah, enemies having the advantage by default can get annoying.