I think one rumor was that Christian Bale was going to play Robin Hood back when that possible angle was being floated around, but for all I know that was just a bunch of misinformation.
I just uncovered a page from the original Nothingham script. It reads:
INT. ROBIN HOOD'S LAIR - DAY
Nottingham is tied, hanging. Robin Hood walks up to him. He scowls like a motherfucker, and speaks in the deepest voice thought imaginable. Like, this voice is unnaturally deep. It must surely hurt Robin Hood to speak like this, but he speaks like this anyway. Why? Because he's fucking Robin Hood.
ROBIN HOOD
You and me. We've been at war. Since before either of us even existed. You tried killing my wife, Maid Marian. You killed my best friend, Will Scarlet. You will not kill me.
Sounds pretty intense. I think Bale was perfect for the part.
John Of England: Where do we begin? A year ago, these peasants wouldn't dare cross any of you. I mean, what happened? Did your - did your balls drop off? Hmm? You see, a guy like me...
Sheriff of Nottingham- A freak!
[men laugh]
John Of England: [ignoring] A guy like me... Look, listen. I know why you choose to have your little...
[clears throat]
John Of England:...group therapy sessions in broad daylight. I know why you're afraid to go out at night... The Robin hood. See, Robin Hood has shown Sherwood Forest your true colors, unfortunately. Friar Tuck? He's just the beginning.