First, some raw numbers
How about Hornet Queens five creatures, all with deathtouch
C Common Night Dragolich X DARK Level 4 [ WyrmEffect ] ATK 1700 DEF 0 Change all non-Wyrm-Type Attack Position monsters that were Special Summoned from the Main or Extra Deck to Defense Position
Demonic Tutors always an option, but these styles of deck get to play rarely-used tutors like Infernal Tutor and March of Burgeoning Life to great effect
Now that we've finished all of this (actually, in parallel with a lot of the edge-case fixing, but for the sake of this article flowing in a coherent way), we get to start on the complicated half of battles
(The wording on Ravages of War [from War of the Outer Gods] implies that, without such wording, the enemy would indeed exhaust.) A: Yes, with the rules as written, if an enemy attacks as if it were the enemy phase, they would have to exhaust after performing the attack (unless otherwise specified)