Not a gearhead (altho my family is...) I just know I have an older heavy steel trailer with a tack area (not really a room). One of my horses is a draft cross, and when he moves in the trailer I would prefer to stay in my lane. My last 3 vehicles have been Ford Expeditions with the towing package that Ford offers, wired to add electronic brakes. I also have sway bars on the trailer. This combination is wonderful. Easy to tow for sure. Very stable and feels secure. I do not, however, ever take 2 horses-just one HUGE one, and my "portable tack store"......lol. AND I get about 17 mpg when pulling. LOVE it!
My best friend has an Aspen ((Chrysler, I think)-totally SUCKS to drive a trailer with. The vehicle is enough lighter that you feel like the horse is driving. Not a good feeling. She gets about 10 mpg.
I have 4WD because I need and like it for other reasons. Not necessary to pull with, depending upon terrain. I do use it from time to time returning my trailer to its parking spot up a grassy incline when it is wet.