I find your comment
I find your comment interesting that you assume a diesel-powered SUV would be able to tow 10,000 pounds. That would take a LOT of work and require a much heavier frame. It would end up probably being classified as a heavy duty SUV.
Consider this, the new Ram 1500 EcoDiesel truck maxes out at 8,260 lbs. The gasoline 5.7L Hemi tows more than 10,000 lbs.
Just because it is a diesel, doesn't mean it can tow more. There are a lot of other factors.
The ultimate problem is the ride comfort of the Yukon would be significantly altered in a negative way with the upgraded frame and suspension needed to tow that amount. No way around it.