User blog comment:Crimson Storm Mich/Future Units Preview/@comment-25741259-20160416040809/@comment-2061246-20160416041230

SP Skills don't work like leader skills, so they won't stack nor have a 100% chance of being AoE. It's unique to the own unit.

Although the chance of having all units do an AoE normal attack would have promising results if you are lucky enough to have them all AoE.