Had to clear this camp of orcs about 50x and killed the Chief about 8x to get this to drop.
Extra 650 HPs, not bad, however as others have stated, this buff won't stack with everything but does stack with most.
Is 650 extra HPs worth this much effort? Not if you made it a real camp. But I just bound my druid there and ported in whenever I had a spare minute, cleared the 3 orc placeholders and kept at it until the Chief spawned.