Idk, I understand the Team's argument, but I don't think that Khamûl's mace is reminiscent of the Witch-King's weapon. The Witch-king doesn't even use a mace, that is a heavy flail. I also don't agree that a huge mace doesn't fit a building destroyer, if there is a weapon that can harm a building it is that one.
But as said before the thing won't work with the animation set, so there's really no discussion here.