Explain the paradox of the apparently contradictory nature, of the witch's greeting to banquo in scene 3: "les?

On the one hand, Banquo wil be lesser than Macbeth because Macbeth will be king, but Banquo will not. On the other hand, Banquo will be greater than Macbeth because he will remain honorable, whereas Macbeth will commit treason and murder in order to obtain the throne.