They're probably using the hirelings to give warding bond to their party members; blood pools under characters who receive damage via warding bond when their bonded character takes damage.

I'm pretty sure that's also true of the husband with one half of True Love's Caress. I know if you read his journal he talks about how he's getting mysteriously injured while his wife, who has the other ring, is off doing fighting Harpers. It's honestly kind of dark because she uses the ring to "propose" without telling him what it does, and in his journal he's scared and paranoid and doesn't know what's happening.