There really is not enough information to form a reasonable opinion from the OP's statements. Many things can lead to premature failure of a tire. Age and brand are only a part of the equation. What is the trailer? is it loaded evenly? does it ride level?
I watched a guy this weekend hooking up his 5th wheel to his jacked up GMC. Nice combination, but with the trailer level, set up for camping, his truck could not fit under the front end of the trailer. They ran the front jacks way up to get the truck under it. The rear bumper was way low to the ground. Not even close to riding level. Do you think that guy should blame the tire manufacturers when he blows his rear tires? I almost went over to talk to him about reconsidering his setup, but I didn't. He must know he's not doing it right... Not suggesting the OP is similar, just stating there is more than what info we have here. Glad you got better tires.