I've been saying it since chapter 619.
As of chapter 621 they have been shown to be rivals and friends.
If you remember the fight between Sakura and Ino at the exams, just as they were about to strike each other for a final time, it flashed to them as children.
That's exactly what happened to Hashirama and Madara, and Sakura and Ino's rivalry were pointed out by Kakashi as similar to Naruto and Sasuke's.
They were rivals/friends and Hashirama cared more about Madara as a friend than a rival, just like Naruto feels toward Sasuke.
History is repeating.
OP's question: Naruto and Hashirama would definitely win.