IIRC, Herc's confidence had been shaken and he was a shell of himself due to the Masters of Evil nearly beating him to death. The Crew was attacking Thor and Thor let himself get roughed up pretty badly, prompting Herc to get his shit together and whoop ass.
__________________ Quotes from Hia8:
"I claimed that the science is sometimes faulty."
"You don't understand. This is fiction. That means none of this stuff really happened."
"There is no writer to purposely ignore a character's natural ability just because it suits the story."
"in some cases because the writer knows that Character A will dominate Character B easily and refuses to allow this to happen for the sake of the story."