They can probably only be used effectively in that way – as cannon fodder. They have аж 13 hit points! With their initiative, speed, and damage, you won’t be able to fight much with them. So, either use them as bait for archers, or teleport the entire squad into the thick of the enemy and let them explode. But for me, they are the most useless unit in Inferno.
Today, I encountered a bunch of demons, and my hero was out of mana! I almost started cursing. I got so angry! And the demons – they just take one step before dying.