Paul Taylor’s words are clear and cutting, without any of the posing or framing that we see in either Lange’s photographs or Agee’s prose. It is with an air of professionalism that he describes the scenes in which he and his wife find themselves, the issues that crop up in the tangle of human beings and economics that was the mass migration of workers.
This clarity serves to both portray the issue faithfully and set the stage for the much more emotionally laden photographs. His focus on the big picture is balanced by the grit in the knuckles of the workers captured by Lange, or the ripped up shackles on the roofs. Although in the introduction, Taylor expressly states that: “In this work of collaboration it is not easy nor perhaps important to weigh the separate contributions of each author,” it is difficult to say whether or not this is true. Through participating they have each given the work their own lens– their own perspective. Without the work of Lange, they would not have the detailed clarity, the heart and soul of the piece. Without Taylor, they would lack the wide scope of the field– the economics of the problem. Their work goes hand in hand, and although they both helped with every bit, their separate individualities brings depth to the collective project.
Feathery Thoughts 
Your summary sentences capture well the collaboration of the two.