It makes sense cause even on wiki they use those edges to pierce through a target.
text on wiki:
"Each side of the four-inch-wide blade was hammered to a sharp edge, and one blow from it could cut a man in a half. It was not an elegant or particularly efficient sword --- for example, the spikes could be caught in the victim --- but the level of intimidation generated by such a nasty weapon was huge. "
Funny thing about uruk swords that should get a usefull rule other than feint:
"The swords of the Uruk-hai are strangely crafted. They are straight the whole way; however, at the top of the weapon there is a spike potruding from the blade, used to snare a horseman and pull him to the ground. Also, if the sword was held backwards, it would still increase pain and likeliness of the enemy's death.
"The upward-pointing spike on the end was an ingenious addition by Saruman, a learned scholar skilled in the arts of warfare. Knowing that he would be facing the legendary Rohirrim cavalry, the additional spike could pull a rider from his horse with minimal effort and either kill or disable his mount. It also served as a terror weapon, sending many shivers down the spine of even experienced soldiers."
So they could use for 2 methods, also beleiving piercing strike should come from this, since if you turn them around, they function exactly like a pickaxe.
seems this weapon special rules only benefits goblins the most since their puny fight and armour makes no diference to soo cheap and numerous horde.