Also where do people get the idea that MCH is this crazy RNG-fiesta class? It's not even remotely comparable to AST.
Every time you're firing your first two primary GCD attacks without ammo, it sure feels like RNG to me (which is rather often, considering you can't just have ammo up all the time). If anything you're playing the RNG more frequently than AST does, because at least with them their card draw is only every 30 seconds.