Let's say you use Cerberuses to rush forward and deal significant damage.
At the same time, everyone summons troops from the underworld (including Archdevils).
Your dogs are killed, and Nightmares rush forward...
From the killed dogs, your main Archdevils summon Cave Lords; meanwhile, more Cave Lords arrive from the gates (summoned by your main Cave Lords).
Your Nightmares are killed, but by that time, new Archdevils have already been summoned, and they summon Cave Lords from the killed Nightmares.
The Cave Lords summoned by two squads of Archdevils can also summon Cave Lords from the gates.
In total, you have 6 squads of Cave Lords! What do you think of that?! What can you do against such demons in a decisive battle?!