1. You can't.
2. I've never used this method before and I don't know is this intended or it's a bug, but format of parameters is an array in format
array('recordset_name' => array('first_field_id', 'second_field_id'));
You don't have to supply the rest of fields.
It's strange that you have to supply your recordset name...
Little example for contacts
$this->rb->set_table_column_order(array('contact' => array('first_name')));
Regards,
Adam