Activate simple the Shuffle Mode of the slider via the option shuffle:"on". It reorders at load the slider, but till new load, it will stay in this order.
<script type="text/javascript"> var revapi; jQuery(document).ready(function() { revapi = jQuery('.tp-banner').revolution( { delay:9000, startwidth:1170, startheight:500, hideThumbs:10, shuffle:"on" }); }); </script>