MPG 2017 3500s pulling 22,800

Just looking at the miles on each truck, the Ram had 1762 when they started, the Chevy had 1170 at the beginning, and the Ford showed 730 at the start. These trucks won't break-in and get their best mileage until much later. The difference in miles could also be why one gets a little better mileage than another. Also, I'm not sure what the 2017 recommendation is, but my SuperDuty was not supposed to tow until it reached 1000 miles. I wonder if it is impacting the performance?