I disagree. Not sure how common this workflow is, but I write by putting all the different unsynthesized ideas down and rearrange them as the latent structure "reveals itself." At the end you have something synthesized.

Sure some type latent structure was there all along (thus why I put them down), but it wasn't necessarily visible to me, nor optimal, nor did it include/exclude all the right points. The need for iteration itself proves that the act of writing is actually doing the synthesis.