Exiss advertises a 2 horse, slant load all alum trailer WITH a dressing room (their S20 model) with a 3,100 trailer weight and an empty tongue weight of 280 (9%).

Trailer is 7 ft tall, 7 feet wide and 15 ft long.

Is this stat regarding the empty tongue weight accurate for this model trailer (with a dressing room)?  Can anyone venture a guess as to what the loaded tongue weight would be with 2 horses?  

I don't much about tongue weight but it appears that TW is an extremely limiting factor on the max that you can tow.  Even an F150 cannot tow more than 500 lbs with a convential hitch according to manufacturing guidelines.

I don't understand how everyone is towing 2horse BP with SUV's and 150's trucks with a convential hitch and not exceeding their max capacity (without adding weight distribution).

Can anyone please explain?

I would say most of the trailers you see going down the road ARE overloaded according to the vehicle builder.  I know that GM requires the use of a WD hitch when the trailer weighs over 5,000 pounds.  Your trailer example would need a WDH if you had two 1,000 pound horses.   Yet, I see lots of people without the WD hitch too.

Can't protect everybody from their own ignorance.  I just keep my distance when I see such a rig on the road.