In my opinion, it's highly unlikely. Goku has mastered multiple forms and techniques that give him a wide range of powers. Saitama's one-punch style might not be effective against Goku's diverse skills and battle experience.
I don't think there's a clear winner. Both Manga Goku and Manga Saitama have unique and powerful abilities. It could come down to strategy, luck, or even the author's imagination!
In the manga, Gohan never managed to defeat Goku. Their battles often ended with Goku coming out on top or the fight being interrupted for some reason.
Goku's victory over Hit in the manga was the result of his perseverance and the ability to surprise Hit with unexpected moves. Also, his experience in battles played a significant role.
The relationship can be explored through their power dynamics. Arceus is the creator, all - powerful, while Giratina is the banished one, yet has its own great power. Their interactions could start with Arceus trying to control Giratina's actions in the fanfiction, but Giratina resists. This power struggle can then evolve into a more equal relationship as they get to know each other better. For example, they might start to share their views on the Pokémon world and the balance of power within it.