Ancient Skull or Devouring Diadem for BAMA?

So far I have used the Ancient Skull on my BAMA Voltaxic Necro but I see most builds choosing Devouring Diadem instead plus spectres (which won't stay alive with the Skull). It seems to make sense because you use a lot of points to get to Eldritch Battery otherwise but when I change my POB and use those extra skill points for a (very expensive) cluster then the damage seems to be basically the same. And that is assuming that both spectres are alive and frenzy/power charges are fully up. Am I missing anything that POB is not telling me? Should I just stick with Ancient Skull and use the minion sockets otherwise?

As an Ancient Skull user, I often find it hard to beat. Support minions can be somewhat counter-productive with BAMA. BAMA requires little investment in minion survival, but support minions do need that investment, or they die frequently. The idea is simple: you don't need the extra DPS from support minions when you're just running maps, but you do need them when facing difficult content. Yet, these support minions tend to die right when you need them the most.

The investments needed, coupled with the socket-consuming and dying nature of support minions, make them less worthwhile. Just my thoughts.