
To make things easier, replace your good Overlords with useless ones before losing.

Overlords are captured, so if you want to keep them, you will have to complete a rescue mission later. When losing a fort, you do not lose Warchiefs or Overlords. For more XP, add White Gems to your armor for a small XP buff.

You get approximately 50k XP for successfully defending a fort, while you get approximately 160k XP for failing to defend a fort and then retaking it. You earn a lot more experience by retaking a fort than you will successfully defending it. The best and quickest way to gain lots of XP in Act 4 is by losing your keeps instead of defending them.
