This information is based on my experience working in People & Culture:
Coming into an environment where everyone is tenured brings about some challenges. Everyone is set in their ways and relationships have already been established. It's difficult to bring change in an environment like that without coming across as combative for implementing a new process or asking questions. Enforcing a new process is challenging. Particularly when Management, Director's and VP's know that they can cut through the red tape by going over your head and complaining to your management team. New rules and processes don't apply to them, they know our management team will make an exception because they've done it before. And will continue to do it. It'll constantly be an uphill battle unless management stops making exceptions, regardless of the title held by the other party. Unfortunately, this is the norm and not the exception. You'll be told to embrace the grey area. Which is difficult to do since it is everchanging.
Just because there is a Performance Improvement Plan doesn't mean you'll be given the courtesy of being put on one before you are fired.