Ah, that battle-first did this on a co-play with split screen and we stumbled through it with lots of eldritch blast etc. Then I watched my wife do a solo play and for this battle she cast Hunger of Hadar where the conjured dudes had to pass through it - they really got bogged down in it which allowed her to focus on the Death Shepherds and the battle was fairly easy then her Karloch beat the crap out of them.
