In The Prince chapter 6 why does Machiavelli advise new rulers to aim much higher than their real target?

Machiavelli urges the rulers of new principalities to follow the example of great leaders of the past (of which there are no shortage in The Prince) in order to "imitate those who have been supreme, so that if his ability does not equal theirs, at least it will savour of it." He says that these leaders will be like archers who aim high in order to hit a distant mark. They hit it not because of their extraordinary strength, but because they are clever in aiming high. The subject of the chapter is "New Principalities Which Are Acquired By One's Own Arms And Ability." Machiavelli invites his readers to consider the examples of such leaders as Moses, Cyrus, Romulus, and Theseus, men whose leadership over new principalities forced them to develop new approaches and strategies. They combined guile, ability, and the frequent rest to violence in order to rule their new lands. If rulers followed their examples they could rule their people well, even if they lacked the talents of these legendary rulers.
https://www.gutenberg.org/files/1232/1232-h/1232-h.htm