Hello!
I know the thread is a little bit outdated, but maybe my solution still helps someone out there.
I had a similar situation and needed to refer to child resources through the whole website.
This might be the site's structure:
Home (1)
+ Services (4)
| + Webdesign (17)
| + Databases (18)
| + MODx (19)
+ Contact (5)
| + Success (12)
+ About us (8)
+ Testimonials (9)
On every page I have the same quick navigation, that shall lead us to "Webdesign", "MODx", "Contact" and "Testimonials" and I want to have it sorted in exactly this order.
With the already mentioned approaches I could not come to any conclusion, on the container pages ("Services", "Contact", "About us") the resources were displayed in a completely randomized way.
I found a solution after adding the "&debug=`1`" parameter, that writes the generated SQL statement to the MODx log file.
After that I added a "where" statement to my "getResources" call, so it now looks as follows:
[[!getResources:default=`[[%nothing_found]]`?
&tpl=`itemJumpTo`
&parents=`0,4,8`
&where=`{"modResource.id:IN":[17,19,5,9],
"modResource.parent:IN":[0,4,8]}`
&includeContent=`1`
&showHidden=`1`
&sortby=`FIELD(modResource.id, 17,19,5,9)`
&sortdir=`ASC`]]
And, what to say? The generated output is exactly the way we want it.
I hope you might find this usefull.