Naive and ominscient points of view in McEwan and elsewhere - and why rewrite Hamlet, anyway?

Ian McEwan's novel Nutshell draws so much attention to the narrative device - a tale of marital distress told by the fetus in utero, able to comprehend everything he (I think it's a he) overhears and bring to what's overheard a lifetime of knowledge and perception - in other words, to be a novelist much like Ian  McEwan, complete with acana, pedantry, and names checks - that we're in danger of losing hold of the plot itself. McEwan opted to make this a contemporary retelling of Hamlet - woman (Gertrude) and her lover (Claude) plot to poison her estranged husband/Claude's brother. What's missing from this equation? Hamlet! I suspect McEwan may have a trick or two up his sleeve, so to speak: Is the narrator/fetus to be named Hamlet? Is he actually going to play a role in the story, aside from telling it? I suspect, as he overhears the plot, which involves his being largely ignored by his father, that the fetus will act in some way so as to spoil the plan and solidify the family - maybe. If not, then, what's the point? If the narrator plays no active role, my thought is that McEwan has made this work overly complex and clever and would have been better off telling a simple tale of infidelity rather than a retelling of one of the greatest works of world literature. Is there any way in which this novel can actually shed light on Hamlet? Make Hamlet greater - rather than diminish it by squeezing into a contemporary setting, ill-fitted? Tall order, so to speak, and maybe McEwan's up to it. I keep coming back to thinking about What Maisie Knew, in which I child overhears evidence of infidelity but doesn't truly comprehend what she has heard - one of those rare, odd, and effective cases of the naive rather than the omniscient POV (the child doesn't narrate the novel but her limited perspective on events makes us much the wiser, more troubled and disoriented). It's a gag, a stunt, to have the fetus so omnivorous - not sure what it will gain for us, though