Displaying the sort icon is a little misleading then, no? It is indicated to the user that this functionality exists, and I think there is a strong expectation that it exists. I would certainly take this point of view; it is very strange that I can click that header and the first and second options I am presented with are to sort.
Can you please indicate how to go about reordering these columns programmatically? would rather implement something to present the data correctly, than leave it in an essentially random order. I have tried digging into the datasource and rearranging the contents of the _columnBuilder object (amongst others), but have had little to no luck.