Scepter Range?
Projectiles that have an arc tend to travel beyond their indicated range. Orb of Wrath, however, has no arc and moves slowly. I think that because the Inquest Golem’s “targets” move around so much, the Orbs of Wrath aren’t able to connect efficiently.
Necro staff has no arc, DS#1 has none, Lich form has none – all hit that Golem from the barrel, so it’s not that.