The group ended up getting a good system going by turning into splinter groups. This meant

Group one/two were screwing together the frame.

Group three/four were nailing together the flats to the frames.

Finally I was routing the frames off. This was needed on about 75% of the flats just to get a nice clean finish to all of the flats. To do that safely I also needed to have someone with a hoover following me along to extract all of the dust and wood shaving which were being generated.