Apple cannot afford to get too big or too disorganized. That’s my takeaway from yesterday’s shocker that not only is Scott Forstall out at Apple, but also that his fiefdom is being split between Craig Federighi, Eddy Cue, and Jony Ive. We learned a lot about Tim Cook yesterday.

First: retail chief John Browett was surely done before we on the outside even heard about his scorched-earth penny pinching. My first thought when those stories started to hit was, If this is true and Tim does not fire him, there’s a problem in Cupertino. What’s telling is how long it took. I suspect Forstall had worn out his welcome long enough ago that Cook held onto Browett for a single press release. Canning Browett so soon after hiring him, then losing Forstall just a few months later, would have shaken a lot of confidence. Losing Forstall sooner would have disrupted teams and product launches. There’s only one headline now, and it’s framed in a proactive manner. From a cold business and PR perspective, I’m very impressed. Tim clearly knows every side of how Apple does things.

Forstall’s star shot upwards from a low level to standing alongside Bertrand Serlet — the man he worked under for years. When Bertrand left Apple, I was sure that Forstall would press to expand his influence, even if he wasn’t given Bertrand’s turf. When Steve departed, I felt the same way. I’m not surprised his style continued to ruffle feathers, but I’m shocked that it cost him his job. I underestimated Cook. Scott’s absence from the iPad mini event last week should have been more alarming to everybody.

If this was only about Forstall being a problem, though, Apple would replace him. They clearly aren’t: the same press release explicitly states a search is underway to replace Browett. Not only is this a profound increase in responsibility for all three of these top executives, it’s a profound change in Apple’s organization going as far back as I can remember. There’s a long-standing pattern of separating watershed products important to the company’s future. The Mac and Apple teams. Mac OS X and Classic. The iPod division. iOS and Mac OS X. Suddenly, Tim Cook has pulled the reins in. Federighi owns software. Ive owns design. Cue owns services. Period.

Apple’s insane growth has pushed the situation over the edge. Too much size and separation inevitably bring politics, chaos, dropped balls, and finger pointing. None of those things are good for Apple’s products or customers. What we don’t know is whether burdening Cue, Federighi, and Ive even further will actually improve things. These guys already had enough to worry about. The worst case scenario is one where good leadership is spread too thin, and everything suffers. These are real growing pains.

Four hundred million devices and five hundred billion dollars later, Apple is different. It’s just finally starting to look that way.