This is a huge issue. Since the Ai vs Ai death has been enabled, I've stopped playing since it basically ruins your save.
A few issues here, first of all, the 2% seems like 20% because the battles are endless which makes the possibility of lords dying seem much higher.
Another major issue is that when you start a save, some clans have barely any members in them. TW needs to add more adult clan members and children at the start of the game, for gods sake.
Lastly, even younger npcs can die which is incredibly frustrating. Young ones should have a less chance of dying in battle compared to older members.
Won't be playing again until this issue has been resolved. It's a complete game wrecker.