You are right mostly back and forth because Thor chooses not to fight. I believe the Hulk was enraged coming into arena like you believe he was groggy in Hulkbuster fight. I cannot see how that would make Hulk less dangerous, I do not believe even if Hulk was impaired the Hulkbuster suit would prevail. I think it goes back to the movies are different than the books. That being said Hulk does not and will not match up well with Thor or any of the warriors to come on their power level in a gladitorial setting. I think in end it is all fun.
And you are arguing most of my points, especially that the MCU is not the same as the comic book universe. I have yet to see the madder/stronger aspect shown with any accuracy. The closest was when the Abomination held the Hulk against the wall, when the fire looks like it will blowup throw helicopter (2008 film). The Hulk had a burst of strength to get out of the Abominations grip.