I did this quest for the first time today. It is hard.
Comparatively, Bloodtail Kobolds is a 4-9 quest, and rewards very well, and is relatively easy (in comparison).
Maybe adjust the max levels a bit?
Area: PLanar, Water, Tehoto.
Alternatively, maybe tune down the spawns a bit damage or AB-wise.
They hit like a truck and there is quite a few of them.