It's a level 6 weapon, so reintroducing minimum requirement to use a weapon would most likely solve this problem. Increase costs for autoattacks to 1 AP per 2 level difference, rounded up. If you are two using it would need 4 AP for an autoattack, for level 2 the same. Or a more classic way: You need XX strength to be able to lift it and use is for any kind of attack/skill.
