Wc3 weapon attachments can only display "stand", "birth" and "death" animations. They will never run any other animations, not even attack animations. The creator is free to upload it as a "weapon attachment", but even weapon attachments needs "death" animations as a bare minimum (But just one where the weapon dissapears). Additionally, it must then fit the attachment points of a unit, such as villager, marine, ect. So it can be attached. I also suspect it will have to be scaled down in that case.