I'm not sure what you mean by they have only have one gate? Both horses are for beginner/basic riders so I'm not going to train them in any fancy gates-because they don't have them I will agree with that. However, I do expect them to perform in all four basic gates, walk, trot, lope, and gallop. Maybe I'm misunderstanding you?
I don't think it will be hard to train these horses to be trail horses. I already got the gelding to lope and I only had to ask him twice. The people who own them got them broke to drive and they really didn't do much with them. Every now and again they would hook them up to a wagon. These horses are by no means stuck in their ways, not at four years old and hardly any driving hours other than with the trainer two years ago.