Inferno’s main forces.

Well, if you always attack Imps and Archdevils first, leaving Pit Lords and Cerberuses for later, then Demons would crush everyone.

And what do you suggest?

Not killing Imps on the first turn if possible?
(You probably like playing as Mages, and you don't have mana problems!)

Kill Cerberuses (they are killed quickly, but even so, they usually manage to attack first and deal significant damage), and after that, Archdevils summon Pit Lords???

I suggest reducing the number of Imps with the first attack (I like playing as Dark Elves), Cerberuses will attack first in any case.

Then, direct the main attack at Archdevils (before their turn, no one should be killed), and after the Archdevils' turn, hit Cerberuses, finish off the Archdevils. In my opinion, this is the right tactic.