Think people are underestimating Mogo by a fair bit. I definitely think he could KO Hulk regardless with one planet sized ring blast but he will ultimately lose to Galactus imo. But of course Galactus doing what he's been doing for the last 20 years despite having no real amps or nerfs but still managing to fail spectacularly in almost every appearance loses because apparently it's now in question whether Odin could beat him or not.
It's a draw and that's not counting Hulk. Hulk cannot inflict lasting damage to Ego and would most likely be over run by the class 100 plus mini me's that Ego could make. I think they drag Hulk underneath the surface of Ego then he becomes like a piece of gum taking 5 years to digest. Ego/Galactus looked like a draw when they faced each other on panel but I'd personally give Galactus a slight edge. It would be impossible for big G to set up his planet eating equipment but he could still try to drain Ego using just his own planet eating ability. I could see a small portion of Ego being drained which causes Ego to flee but I also have the tiniest doubt that Ego can be drained at all by big G.