In a multiplayer match you can use the advantages of the defense buildings without extra focus to the game and resource loss.But if you want to make this tactic properly you must certainly prepare yourself any drop tactic ,if you can not prevent the drops this defensive tactic will fail.Here the best advantage of this tactic is its low difficulty,high efficiency and very high strength properties.If you are P or Z you will construct at your strategic location lots of cannons or sunkens then you will construct tech buildings and you will take exp with the protection of these lots of defense buildings.But remember no drop tactic can harm your resource site!Then after you have expansions you choose technological development or massive development it will be dependent to your enemy and your desire.This building defense tactics are widely used and if it is used correctly it will bring you victory.