In matsubayashi ryu we use naihanchi dachi, essentially shoulder width (maybee a little wider) kiba dachi (toes forward, not out).
I have also trained the kata from shiko dachi previously and find the higher stance (not disimilair to sanchin dachi width
) allows far better structure in the kata, greater power generation, control and flow and makes alot more sense when looking at applications.
Its just my expierience and obviously i respect others have different expierience. And in fairness i have seen older chinese versions trained from very low horse stances???
I like the fact i train sanchin and naihanchi stances the same width, it gives me a good structure to base my karate on, its also the width of my freestyle stance - keeps it all simple for me!