NPCs composing that spawngroup :

a_cracked_skeleton (50%)

a_putrid_skeleton (50%)

a_wimpy_skeleton (50%)

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

befallen_a_skeletal_excavator18, range=85 (-297,-10,-11)

a_skeletal_excavator (100%)
a_skeletal_excavator (100%)

befallen_a_plague_rat20, range=87 (-139,-25,5)

a_giant_rat (50%)
a_plague_rat (50%)

befallen_ariam_depoper17, range=27 (-246,-39,3)

ariam_depoper (100%)

befallen_448313, range=95 (-294,-115,-11)