Yes. Although in my case when I was talking about my 'best managers', they were also the people who were brilliant and were really good at the tech side too. These people all just had a natural ability to navigate through the political BS while still being extremely competent software folks.

Looks like those people were truly "full stack". From the tech layer to the interdepartmental layer.

Yes, as much as I hate that term it really does apply here. And I'm really only thinking of 2, maybe 3 folks. These were the people who managed to be the most productive members of the team while dealing with all of the manager BS. When you find one of those you do what you can to stay under them.

Mentors and leaders.

HR.

Nope. Those would be teachers and trainers.

So to continue the IT parallel, that'd be setup (hiring and training) and maintenance/debugging (hr complaints and problem resolving) imo. My personal hunch would be that viewing the whole thing in a systems context, the EOs would be engineering. After all, they decide how the company is run at a top level, and either assemble a functioning "people stack" or set guidelines for doing so. In that vein, components/prospective employees are churned out by the education system as a broader whole, and the raw material for that...alright, i think that's taking the metaphor far enough.