I managed it with the Barb, so I think it can be managed with any build/class more or less, so long as you're not a massive weakling. What you will need:
1 Rapier or other +Accuracy weapon, purchased from Heodan
1 War bow, purchased from Heodan
1 Brigandine, purchased from Heodan
2 Potions of Minor Endurance in a quick slot, one found at the encampment, one purchased from Heodan
1 Beer, found in the tents over the bridge
As with all epic fights in Pillars - when your very life hangs in the balance - you will need pre-buffing, so make sure to take your beer before you slap on your brigandine. Attack someone, then as everyone has mentioned run south and position yourself between the horses and the fence. Using the war bow pick off the two caravan guards with shields and Heodan, followed by Calisca and Odema (leaving them until last so their Constant Recovery times out), healing when necessary. Switch to the one-handed rapier, and finish everyone else in quick order. With non-Barb builds a quarterstaff should work just as well instead of the war bow.
I needed both potions and my Second Wind from Athletics 2 to survive, but this character is quite frail and inaccurate (Resolve 3, Con 11, Perception 7) so I doubt other classes would need all that. I also made sure to get the Springberry as there's experience awarded for that (though I think they actually deduct it from the experience from killing everyone anyway, so maybe you needn't bother). I guess it's always worthwhile to sell it to with Heodan for more cash-money, like I do all ingredients in the area.
Edited by Jojobobo, 08 January 2018 - 07:01 AM.