no galactus isnt a celestial, but he would easily defeat all of the listed opponents, they are strong for earthly beings....... but they just could not compete with the cosmic power possessed by galactus
"Destiny sees things as they are, not as we would wish them to be.
He knows there are no stories, only the illusion of stories.
Threads and patterns that appear in the pages of existence, and are given meaning by the observer.
Destiny observes worlds and molecules like motes of dust hanging in a sunbeam.
Every movement, every moment inevitable.
Destiny walks his Garden, a place of forks and paths which combine and part, seeing only what is.
He is surprised by nothing.
There is nothing that can surprise him, nothing that was not already written in his Book."
Galactus has shown vulnerability to magical attacks before... most of these guys are mystical in nature and have various magical powers... plus a few of them are well over Thor level strength and durability
They can definitely give Galactus a fight
Growing Man and Thermal Man are just there as cannon fodder though