As individuals, they are dangerous competitors, and they can’t afford to trust each other too much without some kind of mutual leverage. This could be in the form of mutual equity holdings, blackmail, complex arrangements where each party has exposure, whatever. But even then, trust has limits.
There’s no cabal that runs things with rules and elections at this level. It’s all individuals who are immersed in the systems that made them wealthy. Those systems tend to lead to certain behaviors. That’s it.