I regularly tow with my 406, however, my trailer is limited to about 10,000lbs and I have not towed that much (more like 7,000lbs and for six hours) but the 406 does fine, just note the SLOWWWWWW nature of it all. I have had just shy of 8,000lbs in the bed of my truck (gravel / boulders) and it has to be noted that there is approximately 1,500lbs of backhoe braces, tanks, fluid what ever on there already. No issues, but still SLOWWWWW. I'm note sure that this is a prudent amount to put in, but I do it very regularly. Note that I ain't too smart either.
To make matters more fun, I put in a 12V converter, installed a standard trailer brake controller and fabricated a 24V to 12V relay bank to send lighting to my trailer. The mogs 24V if you haven't filled in that blank, and my trailer is the town bike, so it has to remain 12V. If I had done a neater job, and the Mog wasn't out in the woods I'd start a 12V conversion and trailer wiring thread like I had planned to, but I must deal with the three feet of snow on the ground (three more coming this week) and my less than professional installation before the thread goes out. You guys are much more skilled than I am and I have thin skin.
Anyway, if you tow, the trailer brakes are a really huge benefit, regardless of vehicle.
Of note, my manual says that my mog is rated for 22,000kg towing. That's a lot, just wonder if it is meant for highway or field speeds. I suspect that the rear diff does care.