I think we already did a pretty comprehensive breakdown as to why they're flipping right to Justice League, namely fear of 2015 competition.
The closer they get to production, the more secrets they cannot hide.
This should mean Rock is GL, Luthor or perhaps Darkseid. If Momoa is in, I don't see how he's not Manhunter. Unless he was also trying out for GL.
Always keep in mind WB has denied a lot of stuff that's turned out to be true. If you believed them, then Wonder Woman was never part of this and it's not a Justice League movie.
I think we're looking at a very optimal Animated Series adaptaiton, where Luthor using Kryptonian tech to SETI, and either draws the attention of Brainiac or Apokolips, or Brainiac working as a some type of surveyor for Darkseid, who then sends Doomsday. Those are the pieces that keep turning up in every mutation so far.
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