I think they will be balanced based on points. Take a look at all the other units with crazy guns and big firepower. This faction will be a high cost/low model count army for sure.
Top hat alone has what...flying, a storm bolter, chainsword, dual mustache flamethrowers or guns and a giant face sized cannon. He will need to be 300pts alone. The Devastator Squad will probably be 200pts. And I can't even begin to think of what a flying transport boat with cannons, guns, and bombs will cost.
Also these guys will be a ****** to paint lol