We all know who Galactus did go down against these two powerhouses I believe he was weakened before that fight so I believe a rematch is in order so Galactus just feasted on 5 planets and locates T&A and decides they are going back to kyln will he succeed (first scenario)
Galactus decides that a little help is in order so he recruits Tiamut to assist him. (Second scenario)
Well, if he had just fed on 5 planets recently then he would be bloated and supercharged. Which means that he would be slightly above normal/average Galactus. I still think they are too much for him though, The darkness in between seemed to be handling himself pretty well in that fight. Aegis, lady of all sorrows seem to have some sort of incredibly powerful attack, even on galactus scale. The one she used to take him out with.
With Tiamut the dreamer, then I think Galactus would've been able to turn the battle around and won. Really wish we would see that battle in a "what if" comic ^^
G may be able to do it...he already did it off panel, though he lost to them on panel.
T was actually pretty damaged as well...if you look at the art closely you'll see many cracks in his armor...aegis had none cause ss was just a scrub.
Andy Schmidt also said that the battle is by no means a poor showing for g. He clarified that Thanos prepped T&A off-panel, and ambushed G before he was about to feed...which may explain why the battle was taking place on some planet.
Let's not forget...G was about to confront them in heralds of Galactus #2...he had prepared himself for the battle and sent surfer ahead just to find out their exact location, and was gonna lay down the law on his own. through plot-device, ss did the job for him. So in other words...G was pretty confident about taking them down on his own, but norrin beat him to it.
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"It is unwise to battle the Power Cosmic." - Silver Surfer