As the A2S generator can be imagined as a stack of L1S generators, using the "Line facade01" spline would be recommendable as a Y Spline. To ensure, that in the same row will randomized just the size and not type of used segments, you can use the Selector Operator driven by the Random Parameter in the Generate on > Array Y Row mode. In this kind of style set-up, you can easily handle the Z Fixed Size by another Random Parameter in the Generate on > Segment mode. For further randomization, Material & UVW XForm Operators might be added. Attaching the modified scene. Hope that helps.