Good anchors should be able to hold several times the expected load. Where possible, tie the anchor as close to the load bearing point as possible (like the pulley or belayer). Try to keep the anchor in line with the load you are pulling. Avoid having the anchor load shift as this can weaken an anchoring system. Haul lines are typically integrated into an anchoring system. It doesn't hurt to set up a second belay line to take stress off the haul line for resetting Z drags or as a tag line for when the pinned boat is freed. As stated before, test your anchors under some load and always use a spotter.