1st thought, the energy it takes to spin up 3 small turbos would be equal to or great than just spinning up 1 turbo. This might be negated because they will be much closer to the head and allow more energy closer to the turbo, but its hard to say.
2nd thought, article says 3 small turbos might be cheaper than 1 large turbo. I call BS on this since a 76mm turbo is the same price new as a 53mm turbo. So in my theory I think it would cost 3x as much to just buy the turbos.
Plus all the points mentioned above.