The tow rating comes from the MBS 3500 chassis weight ratings of a GVWR of 11030 pounds, and a GCWR of 15,250, the difference being close to 4200 pounds.
Have you also factored in the weight of a braking system added to the Jeep? It would be light, but still part of the equation.
In the end, the toad is either under 4200 pounds, or it is over.
It’s not uncommon for responses to MBS weight questions to be that the owners know they are overweight, but it works fine so they are happy anyway.
2020 Sunseeker 2440DS Ford, Trekker cap, Topaz paint