Sections and categories are ordered in Joomla, but not in necessarily in alphabetical order. Actually the sections are ordered by date submitted, the newes on top and the oldest ones on the bottom.

If you are using automated software to submit content you have to be carefull because adding new sections will change the down arrow keys sequence on the "select section" drop dowm menu...

That could mean that you whole automation task would be destroyed and would need to be reprogrammed! Not a  very pleasant scenario...

So the best way to keep your ordering as is:

A. Don't add new sections, just rename the existing ones to help you deal with the website  category expansions.

B. If you add new sections, make sure to order them as last, that way they will not affect the down arrow strokes on task automation.

The same applies to Joomla categories.