NPCs composing that spawngroup :

a_dread_bone (34%)

a_greater_skeleton (33%)

a_sturdy_skeleton (33%)

NPCs spawning around that spawngroup :
(Max range : 100)

befallen_54, range=65 (-652,113,-66)

a_greater_skeleton (50%)
a_necro_acolyte (50%)

befallen_53, range=94 (-676,130,-68)

befallen_110, range=97 (-494,95,-76)

befallen_116, range=51 (-540,85,-39)

befallen_118, range=76 (-568,161,-39)

befallen_120, range=83 (-519,130,-39)

befallen_123, range=65 (-571,26,-39)

befallen_124, range=78 (-556,18,-38)