My guess would be real world experience. I know that it has cost me close to $2000 in bent up mangled implements that the dealer had said would be fine with my tractor that were not. We learn from experience and some of us pass that knowledge on. Another thing that I think is wrong about how these implements get rated. Many manufacturers rate by horse power when they should be rating by tractor weight. Horse power is worthless without some weight to get it to the ground when it comes to ground working implements.
If a person was to WORK that blade behind a 5075M, I would give it less than a day before it had some sort of damage done to it.
All of my comments are based on experience, others will vary.