To add to this:
The fact that all mages need to pump up Air in order to takeout magic armor is pretty lackluster in giving us a way to address the armor system since it kills diversity to basically force our hands.
I really don't think you need air, you can just get a high spec in fire or geo and your spell will have better damages as well not only against shield (mind you a little less than air) but against health too.
I guess you can also have your ranger get specced in air so when you use magic arrows you do more damages to magic shield ^^.
It probably works with melee weapons with damagic damages.
The only problem with magic vs armor is enemies can have magical armor but non have physical resistance and armor does't reduce physical damage taken. As I mentioned in a different reply I wish they would use a similar system to battle brother for the armour damage mitigation.
