Without info on the SXS and trailer, (weights, size of trlr, etc) and any other cargo/items in the trailer, it's all a SWAG.
Was the trailer steel or aluminum?
Based on the numbers you posted, you were over on the rear axle by 600#+ but that could all be attributed to the tongue weight of the trailer/SXS combo.
I had an aluminum motorcycle trailer that weighed around 350#, and I could roll & drag it around the yard w/o issue. I now have a heavy steel angle iron trailer with wood floor that I can't move w/o hooking it up to the PU. Post up some details on the SXS and trailer, and maybe someone can help out.
'08 Greyhawk 31SS Traded in
TV 2018 F150 FX4 SC 3.5EB TP/MT