First, talk to HR and their boss. Explain that you are confused about roles; is their role to dictate these decisions? Get clarity on that; is your position expected to be the knowledge asset, or are you just a 'doer', as it were, someone to take orders. If the former, explain that that is not being adhered to, and maintain a dialog with the people you talk to to help get it fixed (HR can work with your boss' boss better define your and your boss' role, to coach them, etc, and possibly, if necessary, reassign your boss or you to a different team, if possible, or let your boss go...or, technically, let you go, though you will almost certainly get an inkling that they do not want to be helpful before you push things to the point they'd feel that step was necessary).
If that does not help, and your role is, de facto or de jure, a brainless 'doer' role, where you're expected to be responsible but not empowered, find a new job.
Seriously.
My wife is in a similar situation. When people make no pretense about the fact that their decisions are based solely out of arrogance (to borrow language from the OP), and their role allows them to do it, and the company sees no problem with allowing a non-knowledgeable resource to make decisions that trump a knowledgeable one, there is no way to fix it from below.
If that does not help, and your role is, de facto or de jure, a brainless 'doer' role, where you're expected to be responsible but not empowered, find a new job.
Seriously.
My wife is in a similar situation. When people make no pretense about the fact that their decisions are based solely out of arrogance (to borrow language from the OP), and their role allows them to do it, and the company sees no problem with allowing a non-knowledgeable resource to make decisions that trump a knowledgeable one, there is no way to fix it from below.