There's no way in hell that the High Evolutionary could challenge Odin in a straight up fight most of the time.
For a huge portion of his history as I've seen, his Herald level with an intellect that allows him to do some impressive stuff but in raw combat power? A fight between him with Thor or Surfer would be competitive. As a matter of fact, I'm pretty sure he avoided a direct confrontation with Surfer recently due to his power level or what not.
Odin wins -- those scans are utter BS, how the hell does Galactus get a fatal heartburn? Who's to say that Galactus didn't allow HE to devolve him knowing that his ship will absorb his energies thus allowing himself to be recreated. Galactus probably thanked HE in what Reed considered his final words. IF galactus wants to fight HE, he will probably shield himself from the ray or counter it. In order for HE to win, he will have to suprise and one shot galactus. I don't see that happening. Same with Odin, on a lower scale.