If you try it you had better have a back up plan and methinks a moorish idol in all of its fragile glory is probably not the best fish to experiment with. Although one could argue that putting mine in with 7 Angels, a mag foxface, a yb hippo, and a nasty Achilles tang was a bit of an experiment. In my defense I added them within a month of each other and aggression is spread out what little there is.
I have experimented with leopard wrasse and Achilles tangs (I have two currently in sep tanks) to some degree but I had some experience and strong logical suspicions that I would be ok- plus I had a swift plan b if necessary (other tanks).
As I said though I don't have any suspicion or experience, nor the knowledge of this species that the other two respondents probably have. My success is just as much dumb luck and buying from divers den as it is my skill and experience keeping expert level fish over the years.
I've only had mine 3 months or so, I would hardly call that a "success" yet. He's doing great, fat as a balloon and eating well, disease free, and acting fantastic but it's an idol...