Currently, there is very little control over the order in which the books appear on the spotlight/storefront, except by publishing them in a certain order, in order to get them in the publication date order. Another way to attempt to control the order of the books is to tweak the customer rating, but none of these ways are satisfactory. Recently I had to modify a cover, and it damaged the carefully planned order of my 32 volumes.
I suggest you create a way for authors to choose the order in which their books are displayed on their storefront. I also suggest you allow us to create sets of books (2 volumes sets) to show which books go together, if not when buying, at least on the storefront/author spotlight.