Read my answer again. It is a diagonal line from the upper left of the hero to the lower right of the goblin (as we are looking at them). Your suggestion indicates you are thinking of a line form the lower left of the hero to the lower right of the goblin.
PS: Another good line is from the lower left of the hero to the upper right of the goblin.
PS: Another good line is from the lower left of the hero to the upper right of the goblin.