Released just 42 days after Jon Favreau’s surprise smash Iron Man, The Incredible Hulk was the second movie to enter what would eventually be known as the MCU, a vast multimedia superhero ecosystem.
However, one major thread remains hanging: the story of Bruce Banner as played by Edward Norton.
These differences open the story up to a reimagining that keeps the Banner of 2008 alive, albeit in the shadows.
In comic book lore, the Hulk as we know it isn’t a condition isolated to Bruce Banner. It takes various forms and is trigged by many different things.
So, as it's possible within the MCU for the Hulk condition to manifest itself in multiple people, it’s not much of a stretch to believe that, if two people had similar devastating encounters with gamma rays, they would both become Hulks.
That's where this theory takes its roots, presenting us with two Hulks: 1) the original, named Bruce Banner and 2) a man who, through circumstance, ends up adopting the name "Bruce Banner."