Chapters aren't 'moved around'. They remain at their schools.
The important thing that needs to be kept in mind is what is the purpose of sections. They are there to provide assistance to the chapters thru the elected section chairs and staff.
Chapters need to keep in mind that section boundaries are NOT walls. They do not prevent chapters from visiting and working with other chapters. Nor should new sections necessarily mean that each section must do their own conference. (many sections have been doing bi/tri/quad section conferences for years).
As a section grows in the number of chapters, this can be difficult for a section chair to support them. Ideally, a section chair should be visiting each chapter in their section about once a semester (fall and spring), and more often as needed. (obviously, a chapter with issues will need to be visited more often, while a chapter doing well won't be visited much). If there are more and more chapters, this can be a larger burden on the section chair for their time. If the section is large in terms of size, that just adds to it.
Florida is a large section, geographically. It takes about 6-8 hour to travel between the farthest 2 chapters. This is a problem for those wanting to be section chair, because if they aren't from the middle part of the state, too often they won't get elected section chair. And as we've been growing, that just adds to it. Past section chairs have had to put people on staff just to ensure coverage over certain areas. In the 10 years I've been involved with APO, we've had few visits from our section chair, just because of the travel distance. Our last chair didn't visit us at all this past year, and I'm uncertain if they did so the previous year.
Thus the need for split up and sometimes re-orging sections. Its for the benefit of the chapters, as well as potential chapters.
As to how it works. In our case the Region staff looked long and hard at possible re-orgs. We solicited feedback from the chapters. We tried to explain the reasons for the proposals. Then we put this before the delegates at the Region Conference for discussion and vote. What was frustrating was the repeated misunderstanding of things. Too, too many activies couldn't get over the concept that section boundaries don't prevent chapters from getting together.