They are testing two trucks with comparable tow ratings, nothing more. Ram has gotten a lot of free press with its 28,000 lb. tow rating and the people at this magazine want to test it against the F-450 which makes perfect sense. Same class of engine is being used in both.
More interesting to me was the testing done by Car and Driver in April 2012 and a year earlier by Mrtrailer.com with 1-tons from the big three pulling heavy trailer loads and running obstacle courses, pulling up the Eisenhower grade and going back down the other side where the engine braking/transmision/exhaust brake need to work well together to be effective. In this last area GM came out on top and Ford was next and Ram had the poorest performance. This is the test that is of most significant for anyone who plans to pulling a heavy trailer around in the west.
When the trailer weight is greater than 20,000 lbs. I would be looking at a Freightliner M2 and not a pickup to get the better transmission and better brakes.