Since all of the enemy units use Gem Weapons/Triangle Adept, it is much easier to counter them using the Weapon Triangle Advantage.
An archer with a dancer/singer or some repositioning tools can clear this map alone, due to the bow's innate advantage over flying enemies. Be wary of Subaki however since he is bulky enough to take a hit or two, and with his Distant Counter/Vantage/Bonfire combo he can deal a surprising amount of damage.