I don't think there's any way to set the sort order for a Resource List TV (without hacking the code). The "where" field is for selection, not sorting.
The default sort is by menuindex, so you could set that manually to get them in the order you want. Note that dragging them in the tree will renumber the menuindex values for you.
I don't recommend it, but you could also change the code in:
core/model/modx/processors/element/tv/renders/mgr/input/resourcelist.class.php (around line 52)
Change:
$c->sortby('Parent.menuindex,modResource.menuindex','ASC');
to
$c->sortby('modResource.pagetitle','ASC');
