Here is some basic tactics.
Clear the camp without ringing the alarm,kill the fucking bear while in the cage,kill all the bandits and named idiots around the camp and lastly just park your people from the right side on the high ground. Also you can poison his wine
What I've done:
-cleared zombies
-talked to bandit chick outside, she wanted to rush in, I said wait for my signal
-snuck in through gap in fence
-Talked to the second in command, got a special Lore check to mention a god, he agreed to help me
-Killed the group of bandits to the south (exhausting most spells) and then the ones in front of the gate (they were easy)
Now there are three bandits to the east and a bigger group to the north. The three to the east are near a wolf pen, I have to keep my distance. When I aggro any of the three, all of them come at me. The alchemist has to be killed ASAP, as does the Brawler (barb). They all take quite a few hits and the hit rate is very low (35% ish). The barb is easy to hit but has lots of health. Whichever two I kill first, the third alerts the whole camp.
Theoretically I can rush the alchemist and incapacitate the other two with laughter/hold person while I whack at them but it's heavily RNG. And you know what, those fuckers never fail their will saves.
I've done every quest I've come across, and explored all the dungeons and other named locations, and I need several thousand more xp to level. If there is a secret area somewhere I can gain more xp I'm all ears.