I don't think diversity of Ethics, Morals, personality, religion, have anything whatsoever to do with casting (Other than acting abilities). That diversity can only come from the way the character is written, you won't get that diversity based upon the color, creed or face of the actor you hire, and you won't get it by putting a prosthetic forehead or antennae on a character
One Day I hope to be the Man my Cat thinks I am
Where are we going? And why are we in this Handbasket?