There a lot of things to consider:
Distance you are towing
Terrain, hilly of flat
Aluminum or Steel Trailer
Number of Horses
Although I would recommend a 3/4 for any type of pulling, we have successfully pulled a basic 2 Horse Bumper Pull Trailer for many, many years.
It had Trailer Brakes which is essential in my opinion on any Trailer Total Loaded weight over 2,500 lbs. And is the Law in many States, some require it as low as 2,000 lbs.
We also had a 3/4 ton with a 6' bed, which pulled a 4 Horse Trailer, it worked because we went short distance, would have preffered a diesel engine for longer distance and the hills...lol..
May all your Trails be happy and safe ones