One of NS1's most powerful features is the Filter Chain. By using our SHUFFLE filter you can create a round-robin answer from any record type, even CNAMEs.
Configure a single record, add multiple answers, and add the SHUFFLE filter to your Filter Chain. If you only want one answer returned, add the SELECT_FIRST_N filter and enter 1 for the count. You can use the Simulate Filters tool to see how the filter will work in real-time.