A solid foundation is imperative for a horse. It makes it easier for future training in the discipline the horse is bred for
I believe that you will receive more from a trusting and willing horse, than that of a "made" horse.
I like to promote natural and gentle methods of horse breaking/training with the emphases of feel.
If a horse learns in its own time, as opposed to being told, the horse will become more willing, which in turn developes trust, which is imperative for the horse to evolve to its full potential.