NPCs composing that spawngroup :

an_enthralled_bulthar (100%)

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

sirens_13, range=90 (24,-225,-23)

an_enthralled_bulthar (50%)
an_enthralled_bulthar (50%)

sirens_19, range=55 (110,-257,-1)

sirens_28, range=28 (104,-175,-135)

sirens_29, range=36 (137,-175,-135)

sirens_30, range=87 (165,-133,-135)

sirens_64, range=99 (29,-257,-28)

sirens_80, range=10 (107,-193,3)

sirens_112, range=80 (179,-158,3)

sirens_113, range=66 (164,-161,3)

sirens_120, range=61 (120,-141,-54)

a_siren_myrmidon (50%)
a_siren_templar (50%)

sirens_121, range=68 (134,-137,-54)

a_siren_beguiler (50%)
a_siren_myrmidon (50%)

sirens_122, range=66 (87,-140,-54)

sirens_231251, range=11 (107,-192,3)

a_servant_walrus (100%)
a_servant_walrus (100%)

sirens_231253, range=66 (164,-160,3)

a_servant_sea_elephant (100%)

sirens_231262, range=99 (29,-256,-28)

an_enthralled_molkor (100%)
an_enthralled_molkor (100%)

sirens_231263, range=29 (104,-174,-135)

sirens_231264, range=54 (110,-256,-1)

an_enthralled_bulthar (15%)
a_servant_sea_elephant (85%)

sirens_231274, range=98 (187,-138,-135)

a_watery_servant (100%)

sirens_231277, range=67 (87,-139,-54)

a_siren_enticer (100%)
a_siren_enticer (100%)

sirens_231278, range=69 (134,-136,-54)

a_siren_seductress (100%)