The voice acting in the Arkham series has been top notch up to this point. That's largely from bringing in voice acting veterans and talent from the iconic Batman animated series.
There's a bit of a shake up going on in Arkham Knight though as several roles have been recast with bigger actors. In this new trailer, it's revealed that Jonathan Banks will be replacing David Kaye as Commissioner Gordon, John Noble will take over the Scarecrow from Dino Andrade and Ashley Greene will step into Orcale's shoes over Kimberly Brooks.
Check out the trailer here:
I hope these are more than stunt casting. Arkham had a good thing going on and it would be detrimental to replace parts with big name actors who are picking up a pay cheque.