Ask yourself who would be better for a live action version of that scene. Bryan Cranston or Jesse Eisenberg?
I think the problem with fandom is the constant second-guessing of things going on behind the scenes, and recasting and re-recasting what the insiders are working on and have not yet completed.
It doesn't matter at this point who I think would be better in a role. I don't know what the script is, or even what the director might have in mind. I know what I'd liek to see as far as production and costuming, but after that I'm willing to wait and see.
Add to that the fact that no one else I know is aware of these things either, and I have nothing but a big pile of speculation and fan wank to look at.
I don't think there was ever any chance of casting Brian Cranston as Luthor.
If movies were left to fans to construct, each one would cost billions to produce and would be days or weeks long. And that's just the theatrical ones. A series run by fans would never make air, because it would be over budget in a matter of minutes and each episode would run several hours.
I prefer to leave casting to those who do it for a living, and then voice my approval or disapproval by whether or not I pluck down my hard earned money to see it.
My opinion, for what it's worth.