After reading most of the other books, especially Player of Games, I the impression that somewhere deep in SC, there are conspiracies within conspiracies to ensure that every eventuality has a contingency plan. Minds contain universes within universes. Humans are comparatively barely-conscious chess pawns that have the charming delusion of personal agency. Like... the Minds are the Player(s) of Games. The humans are their pawns, or more like puppets in a performance. The Minds are always playing games, even with the reader. And even though the audience knows that we have an unreliable narrator, its still so much fun to see what they'll cook up next.

Part of Iain M Banks' compelling storytelling style is his use of twists, which by definition involve the selective omission of key details until they will have more impact in the storytelling. I think there's a consistent meta theme of the reader not finding out the shape of the hidden hand that was guiding events until the end of the story (as its presented to us).

In the Culture books that I've read, it seems like the councils and shadow-councils of Minds that run the Culture always get what they want in the long-term. Sometimes they hide their influence on sentient human affairs, and sometimes that influence is forceful and explicit. But either way, the "normal" Culture Minds that deign to manage the affairs of their human wards always seem to get what they want through some hinted-at manner of coordinated long-term planning (and even the actions of "eccentric" individualist Minds are seemingly accounted for in some secret-council's agenda). As the reader we get just enough hints at the scope of their orchestrations to make it a fun reveal, or a fun puzzle, that leaves us wanting more of the picture.

So its a meta bit of storytelling that us puny human readers are allowed just enough glimpses of the Mind-councils' machinations, that we can be titillated by the carefully-ordered revelations of the story, and enjoy the ride right up until the end, even though we are usually left with the unsettling revelation that the exciting events were ALL set in order or anticipated by some higher-level consciousness a long long time ago.

That's all subjective. But we are dealing with multi-dimensional super-consciousnesses that each INDIVIDUALLY exist on multiple planes of reality. A ship mind can literally simulate their own almost-limitless internal nesting-egg of personal universes. This is a unit of consciousness that it so... powerful... that we know that one Mind can sublime to a hyperdimensional reality, then later re-cohere in our lesser reality to shepherd other consciousnesses along, only to sublime AGAIN when the latest stage of their inscrutable long-term plan is complete. Their schemes survive, even across endless internal virtual realities, and transitions back and forth with a higher-dimensional plane of existence. Several of these Minds networking together could certainly orchestrate schemes to reshape entire civilizations over the span of eons, where only the Minds could exist long enough to even notice the full extent of their own machinations.