At TIM Group, I've followed the advice in your last sentence by hiring the very best developers I could possibly find and imposing minimal "management overhead". Interestingly, at some point they tried pairing, and decided it made them much _more_ productive; they continue to use it extensively even though it is not at all required (these days it is a cultural norm, but not dictated practise).

Just a single experience - a proper academic study would be very interesting if someone could manage it - but it doesn't seem to match your theory.