Create a Random Banner Ads in CMS?

I’m trying to create a collection list that has banner ads (images I upload into the CMS). The problem is… I want to be able to randomly sort the banner ads, but NOT the people that I’m listing in the collection.

I’ve tried nested collections, but I can’t sort, nor was it a pheasable option even if I could actually sort.

Does any one have any ideas to make and idea like this work?

Here is my public share link: LINK
(how to access public share link)