Christopher Alexander writes about this: patterns have got to be ordered.
My metaphor du jour (or de la nuit as the case may be, especially while I write this at nearly 4AM) is a burrito.
Making a burrito could be faster, if i ask you to make the guac while i do everything else.
But if i cut the burrito in half, and we both try to make half of the whole burrito, we're going to save very little time. If any.