"destiny" and kurama within certainly cushioned naruto's progression in the series, however at the sametime it was kurama that held back naruto's ability to have good chakra control, especially with his small body containing such a thing. this is why he struggled to one-hand rasengan and use clones effectively. because of that, hard work was needed for naruto to compensate this, which is why naruto figured out how to use shadow clones to help form rasengan as well as use clones to build up on natural chakra in the frog world when fighting pain. these reasons is why naruto is both a hardworker and a genius in his own way because he utilized his clones in beneficial ways. (that's just one of many examples of naruto's genius through his shadow clones)
Destiny and his uchiha genes did cushion sasuke, however the difference between sasuke from naruto is that his sharingan did not hold back sasuke (well...kind of if you believe his sharingan did not evolve until kishi says so for plot reasons). made things even easier for him as he progressed. naruto on the other hand didn't completely benefit from kurama until he debut in the war arc. with that said, hardwork isn't as important to sasuke as it is to naruto, even jiraiya noted that back in part 1. as for genius lvl, yes, he certainly is. but it was never showcased until mid-late shippuden when he faced deidara and danzo, such as when he used his sharingan and lightning to neg the tobi bombs and deidara's clays in a effective way just as naruto used his shadow clones in an effective way while staying 2 steps ahead of his foe just the same. sasuke doing this is impressive, but what's more impressive is someone like naruto who did not have a good start, manage to close the gap in a such a short time. both are geniuses, but naruto has more feats shown of his genius and hardwork. should naruto be the face of hardwork? probably not, but i think it's fair to say he is a good candidate to be the face of genius in effectively finding ways to cheat years of practice and outsmarting foes with something as simple as a clone. should sasuke be the face of genius. no, but he should be credited.
should also give credit to jiraiya/kakashi for being such good teachers to the both of them. without them, they both would had been screwed, especially naruto.
