This was definitely not as hard as VoK imo. I made it much more difficult for myself by breaking the right wall which made them attack from two sides. I think the number of people coming to attack wouldn't change but having them come through 1 choke point makes it much easier to deal with.
I think some longswordsman with druids can defend well with some forts and towers while the woad raiders go on about their business. The few swan ships at the start can protect the trade line from the flank and can be deleted once you defeat the left base and get control of the choke point.
Another thing I would have done differently is make some sort of a sanctuary for the augur. Can't make walls so maybe like a tower wall or store house wall to keep him safe and sound at the back of the base. I kept him alive for some time but he eventually succumbed because I had him out in the open near my tc.
Fun quest overall and was a close call at the end. You definitely want to avoid that champion army near Brennos. It would take like over a thousand woad raiders to kill it.