They explain that the "crown of a good name" is not really a separate crown but it is realized in tandem with the first three crowns. If a Torah scholar, kohen or king fulfill their position properly with exemplary character traits and following the laws Hashem commanded each one of them, then they will attain "the crown of a good name". If on the other hand they use their position improperly and act in a way not befitting of their position then they will not attain the crown of a good name and will instead create a desecration of G-d's Name.