This is starting to sound like the RV foruums.

Do you realize that a 3 horse 36ft 9808 Featherlite is typically under 10,500#.  Add in a 1400# horse and 2100# in tack and trailer weight is only 14,000#.  Billions of head of cattle, hogs, sheep, and other livestock have been hauled trillions of miles to market in GN livestock trailers behind SRW pickups in heavier trailers.  We are not talking about a 53' 13 horse trailer here, rather a 3 horse and the way it sounds only one horse in the trailer at most shows so I doubt trailer weight is much more than 13-14,000# is why the OPs daughter is pulling it with a 6.6L gasser.

FWIW 2024 2500HD w/ 6.6L Gas lowest GN tow rating is 16,870 for CCLB 17" wheels and the conventionl bumper tow ratings are 12-16,000# depending on tire size.  I gaurantee the GN pulls and handles nicer than a bumper pull and the truck is rated to tow the weight as a bumper pull.  As for the daully, a lot of OTR trucks are converting to super singles for better fuel economy, so long as the tires are rated to carry the weight there is no need for dual wheels.  Take a look at the tire rating on most dually pickups and they way less than the SRW counter parts and while you get 2 additional tires to carry the weight you also loose some of that capacity to extra vehcile weight from added tires.  Additionally, gaining 2000# of uneeded payload capacity while a nice buffer is not necessary.