When restructuring a school to get around registration problems for teachers who teach across divisions it is not possible to delete old division due to risk of data loss. It would make things more efficient if you were able to modify these in any way.
Lots of discussions of this on today's Admin rollover Q&A webinar. Would possibly be nice if you could mark a division as 'disabled' so that it doesn't appear in the dropdowns of other modules if there are no timetables/registrations/sets/year groups for that Division.
We went through this process ourselves and found that (a) you can't have divisions with no year group assigned, so if you are doing a complete root-and-branch restructuring, you have to delete divisions and (b) you have to manually take care of timetable allocations, staff divisions, cover cycle divisions and so on. So, yes, the process of managing divisions could do with some work!