You know, this whole discussion makes me think about the controversy that erupts, from time to time, regarding the works of William Shakespeare. (Stick with me; there is a parallel.)
For the past 200 years or so, people have debated whether one man was capable of being the author of the many works we attribute to The Bard. Are they the works of one man or a conglomeration of the works of many? That's the essence of the ongoing debate, complete with references, citations and irrefutable proof from both camps.
Does any of that matter when Puck frolics about the stage, in Midsummer Night's Dream, practicing his trickery and mischief? Does any of that matter when, in The Tragedy of Hamlet, the observer is faced with real life questions about insanity, incest and corruption?
One man wrote it all or a hundred men put their pens to paper. No matter. "The play's the thing."