It is dangerous to assume anything written on the technical aspects of wootz is correct, at least before Verhoeven & Pendray’s Scientific American article in 2000. I suspect Figiel is wrong in his reasoning - the lines show up more at the edge due to more extensive grinding there, not hammering. The same effect happens in pattern welded material. If we assume the ingots were all roughly the same size, then they would all need the same amount of hammering to be transformed from ingot to blade material.
