Yes, it is. The question, however, is one of efficiency and efficacy. Should the child be naturally intelligent, he will be curious. He will notice all things around him and will see patterns, correlations, and anomalies. He will be able to establish causation naturally. He will rarely need to learn through trail and error as he will have foresight.
To learn something through trail and error...I don't feel is efficient...unless the child can generalize the lesson and apply it to a larger group of thought. It is, otherwise, a way to learn how to NOT do something...there are an infinite number of ways to do something wrong.
Now, if we are talking about running mental trail and error experiments...that is a part of forethought. Having to experiment on something that had adequate evidence at hand and to not be able to figure out a correct path ahead of time is only an exercise in a method of learning for future situations where adequate evidence is not at hand. Learning through trail and error is more accidental I would think (we are talking children here...not part of the scientific method).
To learn through exploration of a successful person's method and examples of successful strategies in life is an effective and efficient way to learn. As one goes through life...many lessons present themselves (so long as the child questions the process in an attempt to delve into the methods or reasons used to establish cause and effect). To ignore those lessons is to ignore experience in life. I think that learning through exploration comes about naturally. All a child needs is opportunity. Yes, playing with children of equal cognitive capability is important...however...being with children of higher capabilities would benefit the child much more I would think.