Where I learned shotokan, we had 2 sets of front stance (Zenkutsu dashi): one for basic techniques and one for sparring.
The basic (and kata) stance was lower, with the feet longer apart (approx twice shoulder width) whereas the sparring stance was slightly larger than shoulder width.
Watching some black and white footage of shotokan katas and training in dojos of other styles, I noticed their basic stance were similar to our sparring stance. In other schools, I have many times been corrected on my stance being too wide.
I remember reading (somewhere, I unfortunately cannot recall my source) that the deep lower stance was actually a secret training method that the original masters only showed their most trusted students. Along the way, the JKA decided to break the secret and have everyone train in low stances.
So the question is:
The deep, low stances: Shotoism to make stances look more impressive, or secret training technique?