Using Talents

Im a bit confused about how some Talents are supposed to be used; For instance, “Mighty Blow” says to roll one melee dice, and “Piercing Thrust” only says to make an attack and if successful… So, I just don’t know wether or not certain Talents roll ALL melee dice that a hero has?
PS
Under the Hail of Stones Talent tree “Accurate” should be changed from Action(Shoot) to Passive.