POSH is absolute nonsense. There will be terrible retaliation if you complain against a top guy. The best solution is to grey rock the narcissist and keep all the evidence for just in case situation. Switch the job immediately.
POSH is just not taken in a good light. The female hr or managers will harass your wife and screw her sense of self esteem. This might end up giving both of you workplace PTSD. Please just switch the job and get rid of this place.
Also read 48 laws of power to handle subtle power struggles at work.
All the best!