Hi Devin,
Thanks for your interest in Syncfusion Products.
To manually set the column display order in gridgroupingcontrol, please follow the steps mentioned below.
1) Bind datatable to gridgroupingcontrol as datasource.
2) Create GridColumnDescriptor object for each column added in grid.
3) Clear the tabledescriptor columns.
4) Add the created objects in own order to the tabledescriptor columns collection.
Here is a sample for your reference in which this has been implemented.
http://files.syncfusion.com/support/samples/Grid.Windows/7.3.0.20/F88461.zipRegards,
Rajadurai