Sounds like Sony may already have their Carnage!
And it is not one of the choices I thought of for Cletus Kassidy, although I still think Walton Goggins would have nailed it.
Per Tracking Board, Star Wars veteran Riz Ahmed is being heavily considered and may have even already signed on.

Fans will remember Riz Ahmed from his busy 2016 where he appeared as Bohdi Rook in Star Wars: Rogue One and the Mark Zuckerberg-esque Aaron Kalloor in Jason Bourne.
While this casting would definitely be an unconventional choice for Cletus Kassidy, Ahmed’s acting talent is genuine.

Even with Sony Picture’s recent spotty history, having Riz Ahmed with Tom hardy (as Venom) in front of the camera and Zombieland‘s Ruben Fleischer behind the camera, Venom should be hitting theaters next year with very high expectations!