[Bat/man]

I don't see giving iron boars berserk.
Iron skin = no nerve endings...

If Marverni wants them to berserk, they have access to the area effect madness spell..(Touch of Madness?) - which has a huge area of effect, no gem cost, and its low research level.

This spell is over powered as-is. Making them berserk conserves a mage action unnecessarily, and makes the spell even MORE useful to other nations.

Leave it as is and raise the price to 6 e. (minimum).