I really wouldn't take Pak's claim of Hulk being beyond Superman as any kind of evidence. Since when is Pak a leading authority on Superman to begin with? It's just him being a fanboy, per usual. It would be the same if, say, JMS was writing Superman and in an interview just started talking about how Hulk would stand no chance against him.
If you look at the wealth of feats of Superman's entire history, and how - like Hulk - his power level/showings can be kicked into high gear when the need calls for it. Even if we assume Hulk/WWH/WBH whatever the hell you want to call him now is definitively and clearly physically stronger than Superman he still needs to overcome an opponent with strength easily comparable to his (and yes, easily is the right word), vastly superior speed/mobility, fighting acumen, ranged capabilities, and the ability to set the pace for the fight, it's not going to be some blowout brawl that's one sidedly in favor of Hulk, no matter what the hell Pak thinks is true.