The name column of the grid table is populated by Mage_Sales_Model_Resource_Order::_initVirtualGridColumns()
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You can rewrite this method to manipulate the format as I decribed here: Magento 1.9.2.0: table "sales_flat_order_grid" contains extra space in customer's name valueMagento 1.9.2.0: table "sales_flat_order_grid" contains extra space in customer's name value (just switch $ifNullFirst and $ifNullLast to exchange their position)