killed sambitas all night last night, got a bunch of marks and alot of other NONE/NONE items which are all associated with the twilight armor qeusts.
Deep in the sambita caves you can kill the sambitas till u get nameds to pop they the ones taht always drop pieces of the quests.
if you kill the leader then rockhoppers with start spawning which drop a whole new set of quest items, and if u kill the elder you respawn the sambitas, rockhoppers are all blue at 51, sambitas are all light blue and blue at 51, so i suggest you make your own decision on which to camp for exp/rewards.