Starting at the top seems like great advice. Deal with the people with power and authority.
Power and authority aren’t often in the same place.
The real power is usually foundational. What happens when humans interact. The way things are around here. Often, the people who are ostensibly in charge are simply choosing from a few culturally acceptable choices, and those choices are dictated by the foundation.
It might seem like a detour, but it’s actually the cause of change.