More Wainwrights by mine to have workers mine more and not transfer goods. But when a Stockyard is placed nearby mines, ensure to untick the collection of resources (coal, iron, gold etc.) to have Wainwrights pick up the collected resources off the mine location to deliver to central Storage hub of your choice. Mine workers has less Transferring Goods percentage this way.
I read this idea from EscapedGoat and thought share it here as we need to help each other 
Another note for Wainwrights is when their door is closed, then add more.