Iron Bane or Destruction, which is better?

[tibbs]

Iron Bane says all armor on all units become fragile and will be destroyed with a strong hit.

Destruction destroys armor in a 6 square area right out without relying on a strong blow to break the armor.

If say, you were being attacked by giants with strong armor, would it be better to cast iron bane and hope your mass of archers can deliver a "strong blow" or not take the chance and just have your mages cast destruction?

I guess I don't know what exactly a strong blow is. Can arrow hits be strong blows?

Thanks,
Chris

[Inigo Montoya]

My understanding of the pros and cons:
Destruction, if you want to destroy armor - limited to AOE of 6, but no need to strike a hit.
Iron Bane, if you want to hit the entire battlefield - the armor is rusty, but not broken. Everytime for the next four rounds of combat that the attack "hits" after damage is assessed vs protection, then the armor has a 50/50 chance of becoming broken and dropping to 0 protection (with exceptions for magical armor, natural protection, etc). Note Iron Bane affects your own units.