New TPMs confuse the org chart with the stakeholder map. They're different documents. The org chart tells you who reports to whom. The stakeholder map tells you who can move your program and who can stop it, which often has little to do with title.
I sort stakeholders on two axes: how much the outcome affects them, and how much power they have over it. The four corners need different handling. High power and high interest are your partners, and you spend real time with them. High power and low interest can kill you on a whim, so you keep them informed enough that they never get surprised, because surprised powerful people say no.
The corner people miss is high interest and low power. These are the teams doing the actual work who don't sit in the steering meetings. Ignore them and you'll learn about problems too late, because the people who saw it coming had no channel to tell you.
The map isn't static either. A reorg, a budget cycle, a new VP, and the power axis shifts under you. I redraw it whenever the org moves. A stakeholder map from last quarter is a guess.