Is the thesis valid described in the book by Karin Gnaoré, The Pikler and Montessori Approach, Sensory Integration, and Psychomotor Therapy: A Comparative Study Based on Research Findings? And while they may be overlapping, are all four of these techniques of value in contributing uniquely to raising well-balanced young?

This, indeed, is the case and is the reason and motivation for this work to exist in the first place. It is written by someone who truly appreciates the value in humanizing the role of the parent in a way that is in divine alignment because it is intuitively recognizing what infants and children represent as an emotional being with keen perceptions, despite uneven development and even lack of language capability, as the very young must go through. But even a baby knows what is fair and what is not. It will have its own biases but that is the point, parents need to know who they are dealing with, how they perceive things, and what is most effective in how to help support and encourage them without undermining them inadvertently by smothering them with over-attentiveness, and moving too swiftly to correct every difficulty and obstacle so there is reduced motivation for self‑sufficiency at the expense of slowing down learning and becoming independent, and so on. This is why there is room for many variations in dealing with such a complex undertaking as parenting the young, and given the cultural distortions influencing human behavior, it will be, in many cases, that breakthroughs come from an unusual source, maybe even someone who is an outlier, because what is taking place is someone with an intuitive appreciation for a new approach gains traction through being given divine support to gain an audience, and then will be supported further for the idea to grow and spread enough to get noticed and make a difference. That is how the divine does its work, always against opposition and resistance, because the interlopers are always one step ahead of you in everything you take on as human beings.