How do you match tractor speed so you can follow each other so closely?  I recall when two of us were in the same field, we worked in different lands so we didn't get in each others way.  Part of that was because of plugging the plow, part was that one tractor was bigger by a small amount and able to run faster by a small amount.  One of our plows was 4-16, one was 5-16, the 5-16 plow pulled by a larger tractor.   I would think from some of the pictures that someone would be clutching a bit to keep running over the smaller tractor.