Told ya :p
But welcome to my world. I saw mine roll of the assembly line and was like oh shit. This is real now. Sold my truck 2 days later for several k more than was offered by the dealer. Then Jeep screws around and let's mine sit in KZOA for 45 days. It's been a rough 2 months without my own...
Look at the GCWR
12,800 for the sport max
12,450 for the Rubicon
Using the explanation of GCWR from the screenshot it can be inferred the lower combined weight of the Rubicon is due to the increase in tire size. This 350 lb loss in combined capacity needs to be removed from the Rubicons tow...
It's easier than the metric crap because it's total height. A 33 is 33in diameter. So your overland has 31ish tires. A 33 will be 2 full inches taller.
I would take a little off of the 1/8th and see what it does. Jeeps tend to like it between 1/8th and 1/16th. Take a couple twists off of the toe and drive it for a bit and see how it goes.
My friend is the guy responsible for the capacity numbers. I'll take his word over yours. Shadows nailed it with the gearing. 560 pounds of trailer weight means little to springs when they only get a fraction of that in the form of tounge weight.
After speaking with my friend at Jeep the biggest difference between the max tow and Rubicons lower capacity is the tire size. Some is spring rate but he said the majority of it is the tires.
So you loose 600ish pounds for every 2in of tire size.