Open the VA Snippet editor and select a snippet in the list. If you now click on the new snippet button the new snippet is added underneath the one you selected. So you can position it where you want in the list.
Also you can simply use the mouse to drag and drop snippets in the tree to re-order them.
We do not auto sort the list, since the ordering of items in the list dictates the order they will be shown when triggering snippets in code, and you are going to want control over this, putting the most frequently used overloaded snippet first. Consider "for" or "if", where there are often more than one snippet. Change the order in the tree changes their order in the listbox.