If a hillfolk is a native Olman tribesman from the Amedio Jungle, they will be nice in the Lucky Monkey Inn but quite out of place in the Kopru ruins.
They replace the thugs from the Dungeon AP, but maybe thugs are better as hard-hitter help to Alleybasher rogues.
Hillfolks are helping Triel/The Ebon Triad only for money, so the are simple mercenary goons?
Hillfolks are helping Triel/The Ebon Triad only for money, so the are simple mercenary goons?
One of the items in Tygot's from the Demonskar Legacy is a monkey mask that was worshipped by local tribes. In the HC, the monkey mask is connected to a cult that actually worshipped Demogorgon.
It is possible that the native Olman tribes worship monkeys, and therefore hold TongueEater in high regard. Triel and TongueEater work together. This contact allows the Triad to "hire" a number of hillfolk into their lair. This would explain their involvement in the Kopru ruins.
You could also substitute gnolls for the thugs in the Kopru ruins. They would be from the tribes to the west (near the Demonskar), which worship Nabthatoron. They could even have been originally Tarkilar's kinfolk (or spies sent by Tarkilar's chieftain to watch him). This provides a tenuous link between the Triad and the Demonskar.
I replaced some hillfolk with gnolls, a bit despairing now with Tarkilar undead and with a low morale, crushed between an undead and untrustworthy humans; and I will replace more hillfolk, both in the inn and in the ruins with thugs, so hillfolk will be colorfull, rare and dangerous (poison using and stealty) foes.