Asssembly modeling practice?

I recently had to edit an assembly model put together by a recent hire. I found that he had used a series of patterns consisting of the parent and one child to place objects along a conveyor system. each successive pattern uses the child of the previous pattern as the parent. I have never seen this done before and am wondering if this is an acceptable practice or if might be contributing to what seems to me to be excessive rebuild time for the assembly model.