Actually most are, even with their V6 trim. Even a mid size Colorado is rated up to 7000.A two horse trailer is about 3500 to 4500lbs. Our horses are both about 950 (they both big boys) so heaviest would be 6400 to 7000lbs. I don't think many 1/2 ton trucks will tow that. Since someone brought up a travel trailer, I will add that as a possibility.
In anycase, my question is, at what point do you look at a trucks mileage and say it has too much.
I bring it up to say I wouldn't want to do it regularly despite the ratings. You'll be much more comfortable with the length and brakes and frame of at least a 1/2 or better a 3/4 ton