Now on maps like C&C_City or C&C_City_Flying then I might be able to see his point. At least in the very beginning. Both harvesters are usually dead no matter what the first time around so if at all possible you should wait to kill their harvester till after they kill yours. This means both harnesters do not get a load in but they will have to wait longer meaning they your harvester will get back ouit there faster.