I can say this about saddle bag guards, they do not stop the bottom of the bags from getting scraped if the bike goes over. They only protect the bags from hitting something when maneuvering the bike and get to close to something or if the bike is lying completely on its side. Skid plates like like the best option for lay downs.
TopShop has Skid Plates in Carbon Fiber, put a set on mine after scraping one side and havent had a problem.(now). They give you rivets and double-sided tape.
I think if you Rhino-lined them you would have to go up the side a half inch or so to get protection.
I just finished my left bag using a more rigid diamond plate cantilevered so it would protect the bag in a lay down. but it looks like I did not cantilever it enough
$65.00, pre cut to fit, stainless, ready to bolt up. Why would you want to make them? I suppose if you had stainless scrap sitting around the garage and the tools to cut it to shape. Stainless can be tough stuff to cut with neat precision for the average home garage dog! Just my .02.