EDIT: Found the other thread after a second search. Feel free to move this there (unless it is really a whole new thread, which I hope)
All (or close to it) of superhero movies have been a solo hero or a team (not counting Avengers or other future possibilities)
A first installment duo movie may be a needed break of the genre movie -wise.
I know there are Iron Fist and Luke Cage threads out there, but let's think about what a writer's or a producer's POV would be.
Business-wise, you got several demographics and audience types:
Blaxploitation or Black audience (not sterotyping, thinking like a businessperson)
A fresh perspective creatively
By the latter I mean you have two people playing off each other as far as coming to grip with their powers as opposed to one person or a team dynamic. You got raw strength and martial skills for action scenes not to mention the drama potential of two heroes from two social classes trying to find a joint goal for themselves.
As a movie goer, it would be more interesting to see a duo origin movie as a concept then just selling me on the franchise...which would also work in this case.