Read the manga, Naruto's control over Kurama's chakra was because he had Kushina's blood, Naruto being able to use the chakra of all 9 bijuu was because of Ashura's genes, Madara requiring Hashi's cells to become JuubiJin was because of Ashura's genes.
Before Killer B all the shinobi chosen to be hosts died because hey couldn't contain the power of 8tails, in part 1 Gaara's body was being consumed by Shukaku which led to his insomnia, in contrast Naruto contained the strongest bijuu with no side effects since he was a baby.
Finally, Kakashi mentioned
stamina being a requirement to control large amounts of chakra and as we know Uzumaki have the largest stamina, you can even see Sasuke's disbelief with the way Naruto is using bijuu chakra
So tell me, how does being a Jinchuuriki not rely on the genes for a strong body ?