Naruto's character would experience significant growth. Sakumo's training could help Naruto better understand the consequences of his actions. He might become more calculating in battles, not just relying on his brute strength. His relationships with his friends could also be affected. For example, he might be more protective of them, having learned from Sakumo's sense of loyalty. And his attitude towards his enemies could change as well, as Sakumo might teach him about mercy and when to hold back in a fight.
Naruto would probably become more disciplined. Sakumo was a strict ninja, so his training would likely instill more self - control in Naruto.
His ninja skills would expand in new directions. Naruto might start to value stealth more, as Sakumo was good at that. And his understanding of teamwork could be enhanced as Sakumo had his own experiences with comrades. Also, Naruto's view of the ninja world could become more nuanced as Sakumo shared his own insights.