I'm not really sure what the physical/magical designations add from a gameplay perspective. You already have a giant red arrow telling you that something is a tankbuster, so none of this was intended as a test of memory.

I will say that if they're committed to damage-type specific defensives, I would like to see Celes' Runic ability added to the game someday. That being said, I know that tanks aren't allowed to have fun defensive moves that provide damage benefits, so it probably makes more sense to give a ability like that to Mystic Knight whenever they decide to make it into a melee dps. Shiiing! MP!