User blog comment:Adlet Myer/Zealous Gauge-Eaters/@comment-16672379-20140201081141/@comment-6881157-20140201083330

1k won't really matter with Drill Bunker since 7k hits most things anyway...

I guess the main difference is that Piercing Spear is usually used to attack first due to its high power and penetrate while Burning Sword is used for direct attacks due to its lower power and lack of penetrate.