Just speculating here, but they may be going the Wonder Woman route where an emotional love story with Diana, a goddess and Steve, a human was basically a central plot line. So he could very well be the (or at least one of) the male lead/s. Dane can easily be Chris Pine in this movie, just with his own history and superhero potential. I think the love story really helped WW resonate with the audience. This could be something great change of scenery for an MCU movie.