He did say that and I think you are right, so if we were to make Akadama, the added fibers to make holes would be a necessity. Yes, clay formation is in plates because of the layering effect of soils. I do have my doubts about this being a needed attribute because the roots do eventually get bigger and break the particles. However, those small areas/tubes would attract water through the capillary effect and increase water retention. I guess I could go both ways on this.
My guess is that this Akadama clay was formed from a slide of some type which mixed it all up. If we make our own, we do not have to worry about that because we would have to mix it like ceramic slip then pour it on a plaster slab to suck out most of the moisture and then compress it.
Good info here. Keep it coming.