These threads are always interesting to me. This truck has 150K miles. Over 50K miles of that has been as in these two pictures. It will climb a 6% grade, on cruise control, maintaining 58 to 60 mph at 3000 to 3300 rpm. Water temp as reported by the scangage never exceeds 204 degrees ( normal is 196 to 198 ). In fourth gear of six, manual trans. An automatic would need to be in third to get those rpm's.
The horse trailer loaded for a show with the quarter horse in it and all the show gear in the front weighs 5300 to 5500. The camper weighs 4100.
I guess I'm not sure what people expect from their tow vehicle. Yes, my F350 diesel dually pulls these trailers more easily, but it's pretty much reserved for the four horse GN or the equipment trailer.
I say it again though, looking at the specs for the trailer in the OP's first post, it's too much trailer for the Frontier.