Martial skill icons ()

While doing some wiki stuff, I noticed from here that

Crafty Defender and Unsteady Defender have the same item icon as other Armor skills, different from Novice Defense and Untrained Defense. WAI ?

 

Are some armor and some block?

 

Nope, those are all Block-based. The Defense ones should probably have the "Rook" graphic, different from the armor graphic/Armor cards ones.