The fight with the Gnolls isn’t hard if you take advantage of the terrain. There designers put a ledge right over them for a reason.
I dunno, I've tried to use the cliff and the archers still just murder me. 3 attacks/round, doesn't reallly matter what your AC is, they are gonna hit you.
I usually have Asterion hide and sniper a few with his sneak attack longbow until they get wise, then he cunning dashes away while shooting behind him until I train them all the way back to just outside Wakeen's rest where I can bottleneck them, problem is sometimes the game just glitches out and they teleport to the cave and kill the Zentium.