How do you compare the two, a "hero" who can beat any enemy in one punch vs bosses that have elaborate final fights, Atheon could teleport him while he is busy with oracles, Crota who lives and dies by Sword logic, you cannot damage him without the sword, Oryx you need to grab fading light and then steal an immunity only to damage him with his chest open in an ascendant realm. I would say One Punch has the highest chance to win against Atheon and Oryx, he could punch Atheon before teleporting or keep mashing at Oryx until he opens his chest. I doubt he could analyze a weakness against Crota before he enrages and summons his Oversoul. He can only be felled by "the sword" so One Punch is used to just using exactly as his name implies, one hit. He might drop Crota to his knee but it is pointless otherwise as Crota would be immune in his Ascendant Realm.