In our primary use case for curricula (e.g., a list of procedure documents that have to be retrained with each revision), we do not use prerequisites, neither item-to-item nor curriculum-to-item. However, we have a second business case in which we did sometimes configure a curriculum as a prerequisite to a course in a second curriculum. In that use case, all of the items in both the prerequisite curriculum and in the second curriculum were courses that did not get revised (one and done). The pre-requisite curriculum was often a sub-curriculum of its parent curriculum. The business need that drove us to use such a complex configuration was because the user needed to complete the training in the first curriculum in order to have sufficient background knowledge to understand the topics contained in the second curriculum. In effect, we used sequential prerequisites of curricula to control the instructional sequence of this "training program".
And then we discovered the Program feature in the LMS. Once we implemented Programs, we built a multi-section Program for each entire "training program". The first section contained the items from the first curriculum, the second section contained the items from the second curriculum, etc., and then we enabled the option "Progress Restriction By completion" to force the users to complete the sections in the order specified. These Programs are working so well that we have dismantled our curriculum-as-prerequisite structure and archived most of those curricula. (Now if we could only get a Program Status report that included optional activities also...)