To wallcheck with Mordor: Send Gollum to your Mill and wallcheck with Orcs. That way you don't have any delays because of the wall-check: If it's FoD, all units are already on the right way. If it's FoL, Gollum takes both Mills and then checks bottom and you change direction with the Orcs to your bottom left Mill (or with 1 Orc so the other scouts middle) the Orcs are there in time as well.