There are too many things that can work out well. I mean, when I was leveling RNG on my old character I had this horrible set-up, but it worked great: RNG/WAR, RNG/WAR, RNG/WAR, WHM/BLM, WAR/MNK. Not even a full party and we were owning pugs. Of course, this was before the RNG nerf and we were all horribly over-powered.