Lyfe Pulley System

Hello to all, we just got a Pierce Lyfe Pulley sytem and been looking some ideas on how others are using it. The Pierce book does use it at 500# anchor back to the turn table and 250# anchor away from the truck. My question is why does that have an affect on anything? In the past on other areials we would use the top fly section (without the escape tip) to rig mostly a change of direction. Does the same principle apply to them as well? I do know using the top fly instead of the escape system will allow us greater weights. Any thoughts?