Provoke does nothing if others haven't put some enmity on the mob that you are provoking, it's better to use shield lob or tomahawk etc for pulling mobs. because they give enmity. Yup it has a nice range but it also has longer cooldown, you might need it when there's a melee dps surpassing your enmity when they are focusing on just one mob, but then again, it can also be easily prevented without provoke.