What to do when Fact is better than Fiction?

or, if your historical figure has already been written about (by Daniel Defoe, no less)?

Long story long: While researching 18th century London criminals, I came upon Jack Sheppard and Jonathan Wild. Originally, I was going to use them as inspiration for my characters, set in a slightly different time period. My protagonist was going to be based on Jack Sheppard and have a Jonathan Wild type as his foil. This has been my work for the last couple months, but lately I hit a rut, and I've never been 100% behind my protagonist.

But now I feel like focusing more on the "historical" and less on the "fiction", basing the story on Jonathan Wild's rise to prominence in the criminal underworld, shading in the details with my own flavor.

My perceived problem is that he has been covered already by the aforementioned Defoe, as well as in other works. I think I can differentiate my take since most of those were of the 18th century biographical narrative mold, and mine would be more of a modern, grittier interpretation of the underworld. But I wonder if this is perhaps too daunting of an undertaking and if I should turn back towards other ideas I have in the hopper.

Thoughts?

My scope would be much narrower than Neal Stephenson's, and not really have any of his sci-fi elements.

Thanks for that additional reference, Chasbaz. And that's kind of what I was thinking about doing; taking them as historical figures but fictionalizing the details between some of the more well known facts about them.

That's a good suggestion, Carmy. I hadn't given it that much thought since I found the historical characters so compelling. I was singularly focused on telling a story from the point of view of either Jack or John (or someone based on them).

But just now as I thought about your suggestion, a new character came into being, one who I think would be worth fleshing out. Hopefully it will work out, or I may table this idea for a while.