Welcome to JOF
The Ford Excursion can be a nice TV, but like any TV it also has limitations....., and one's loading habits can play into any TV's towing ability.
As you may be aware, with any TV it's "available" payload capacity is a critical element when evaluating a particular TT for purchase because a TT's "loaded" tongue weight is subtracted from a TV's "available" payload capacity.
To minimize the amount of guesswork, I would take your Excursion under loaded conditions (full fuel, passengers, cargo) and weigh it at a CAT scale (3 minute process, about $9). Subtract the CAT scale weight from the GVWR noted on your driver's door......, the remaining weight is what you have available for a TT's loaded tongue weight and the weight of an standard WDH (50lbs).
The loaded tongue weight of a TT like the 32TSBH should be 13% to 15% of the TT's actual or projected loaded weight. The 32TSBH published UVW of 7,855lbs isn't the ship weight, IMO the ship weight will be closer to 8,300lbs. If the TT is on the RV dealer's lot, refer to the yellow sticker.
For reference, the following JOF "Excursion" thread may provide some additional insight:
Published Tow Rating Reality: http://www.jaycoowners.com/forums/f37/what-is-my-actual-tow-rating-3866.html
IMO the CAT scale visit will be an extremely helpful part of your do-diligence.
Please feel to ask for any clarifications.