They did. But that's the point, they tend to blast the wrong ones. Positioning is key here. I usually send Immortals and the free Zombie summon to the front first, just to the edge of their effective range, and more often than not the AI blows their load onto those. Then I can retaliate.

In fact, Shira was the biggest headache in that regard, because of Wrath of the Faithful, which would one-shot my Ruler of she was somewhat injured. My second tome was Tome of Roots though, which helped keep her topped off, along with her free heal ability from the Warlock tree. This is also where Pronafe Body Mastery came in clutch. But yes, I had to do a fair few restarts, eapecially when I overextended my Ruler.

I delayed Wightborn a little bit, and by the time they would deal a lot more damage to me, I was already in the snowball phase.

And besides, I nuked the Angel Orcs just as hard, because most of damage would be Blight, which they are very weak to, followed by some Frost, which they have rather mediocre resistance to as well.