NPCs composing that spawngroup :

#Overseer_Dlubish (10%)

a_goblin_backbiter (13%)

a_goblin_blightcaller (4%)

a_goblin_boneseer (4%)

a_goblin_dirttracer (8%)

a_goblin_flashdrowser (4%)

a_goblin_slavedriver (27%)

a_goblin_stalagknight (24%)

a_goblin_stonechanter (4%)

a_goblin_warder (2%)

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

nurga_172, range=3 (-1446,713,-237)

nurga_174, range=48 (-1413,751,-237)

a_goblin_flame_chanter (50%)
a_goblin_spirit_chanter (50%)

nurga_175, range=44 (-1453,756,-237)

a_goblin_death_knight (50%)
a_goblin_overseer (50%)

va_nurga_508006, range=50 (-1414,754,-236)

va_nurga_508013, range=47 (-1453,759,-236)