Bob Wills was likely a very important figure. Maybe he was a musician or an artist of some sort. Since he's called the 'king' in the story, he must have been highly respected in his community or field.
To develop Bob Armstrong's character, you could give him a backstory of having faced a great loss in the past, which has made him a bit reserved. As the story progresses, through his interactions with Bob Barnard, he could start to open up more. For example, if they are in a work - related fanfic, Armstrong could initially be hesitant to take risks, but seeing Barnard's boldness, he could gradually become more adventurous.
One possible plot idea could be that Bob Armstrong and Bob Barnard are two detectives working on a mysterious case. They start off with different approaches but gradually learn from each other and combine their skills to solve the crime. Maybe there's a shadowy figure behind a series of art thefts in the city, and they have to navigate through a web of false leads and dangerous encounters.
Bob Biswas might be inspired by real events or characters, but it's likely a fictionalized account with some creative elements added for the sake of the story.