Subsystems!
I think of ... I was going to say every move, but it's not quite true. I think of most moves as their own subsystems. There's a subsystem for going aggro, a subsystem for reading people, a subsystem for changing Hx... So the game has, from my point of view, a million very slight, very specialized subsystems. They're so slight, and so similarly-built, that you can just make a new one whenever you need to for whatever new circumstance arises.
Only a couple of the moves are in any direct contact with one another. The move for changing Hx is in direct contact with the move for helping and interfering, for instance, through the Hx stat. Instead, most of the moves receive exclusively from the game's fiction and return exclusively to the game's fiction.
(There's an interesting exception in the +1forwards and -1ongoings and those. They don't connect to any particular specific move, they connect to just whatever move comes next.)
It's like pinball! Like a pinball table. The inclined plane is the game's fiction, the marble is the moment of play, and all the paddles and wheels and bumpers and light-ups and flags and whatever are the moves. Their job is to give energy to the marble, make it go faster, with spin, in different directions, unpredictably and excitingly. As player, you have more or less control over your own set of paddles, your own moves, but none of them let you really drive the ball.
Uh... so that's where I'd start. Ask me more questions! Which subsystems are you most asking about? What are you having trouble putting your finger on?