If you must hire an asshole, keep them somewhere they can't do any damage to the culture.
Agreed. Pity that being an asshole can't be determined through some sort of pre-employment screening process. Unfortunately, assholes are often quite adept at using their superficial charm to conceal their true identity.
It's easier than you'd think. The sad truth about assholes is everyone knows. Everyone knows who they are. Everyone knows what they're doing. Everyone knows that management is aware of the assholes, and chooses to do nothing.
No its have proper procedures and training for all mangers FFS its not rocket science.