This is Thor with the Odin Power, his own innate powers and the Power Cosmic.
Odin alone has stalemated Galactus. Thor alone has made Galactus run (part of the continuity you talked about). Even in Aaron's run, old King Thor with the Odin power has had a decent showing against Galactus (and has beaten him with the Necro Sword). Add the Power Cosmic (Silver Surfer alone has been able to fight Galactus for some time)....so, add all of THIS Thor's powers, he should be a match against Galactus....
Not when Galactus was set up to be his most powerful ever by eating those 5 worlds, set up to be a big bomb?