Threat Reduction (Level 40)  

I haven't found the end of the quest repeating yet, but the structure is very simple.

The quest is repeated 10 times at each of several tiers (three tiers so far for me).
At the first tier, you are asked to kill spotters, invaders, raiders, grunts, or catapult operators, all outside the gate.
At the second tier, you are asked to kill sentries, elites, vallon centurions, or miners, all in the mine area.
At the third tier, you are asked to kill sullon lumberjacks, sullon elites, deathfist toilers or sentinels in the northern area.

You must wait a significant amount of time (probably one game day) between each repeat of the third tier of quests. So far I have done Threat Reduction 23 times, and I expect 30 are needed to move onto Cornail's final quest (Never Double Cross a Barbarian).

Anyone know where to find Tallon Invaders for this?

Was asked to kill 10 Tallon GRUNTS at level 29.

AT lvl 41, this quest gives either 8xSullon ELites, 10xSullon Lumberjacks, 10xDeathfist Toilers, 10xDeathfist Sentinels, all near DFC. There is also another Deathfist type but it escapes me at moment.

Quest reward for completion last 4 times has been around 3g 4s and a few copper. Very nice reward for little effort.

This quest seems depend on player lvl to issue diff sets of mobs.
If u are above 38+, he will give u Sullon lumberjacks, or Sullon elites, or Deathfist toilers to choose.

I see we have a list of the lv 31 mob's for this quest, but do's someone have a list for the lv 34 one's?

I just received this quest and it requires me to kill 8 Sullon elites