Actually safety wire or secondary chain is not a bad idea. When we purchased our coach the last thing I ever thought about checking was the rock guard. Fortunately I discovered that the factory and/or dealer hadn't threaded close the links attaching it to the coach before it could have easily come off. Now I give it a quick check at least once day and a more thorough check when I hook up or detach the toad.
2012 Sportscoach Cross Country 385 DS Freightliner XCR w/ Cummins ISB 6.7L 340 hp
2009 Saturn Vue, Blue Ox Alpha, RVi Brake 2