A solution to this would be to only list group headers on the Index and no sub pages at all.
Let me give you an example.
You have a page called [Mountains of the world]?. It is a group page, a mother page if you will.
You write an outline on the [Mountains of the world page]?.
'The mountains of North Africa.
[/The Atlas Mountains]?
'''The mountains of North America
Sub-pages will be listed alphabetically when on the mother page they are regrouped by continent. Weird!
The solution is simply to list mother pages on the index (and no sub-pages) so that the reader is not lost.
Is this patch easy to do?