Large-scale structures like the CfA2 Great Wall exhibit unexpectedly thin cross-sections (10 to 20 Mpc) compared to their enormous lengths (hundreds of Mpc), creating high aspect ratios that challenge ΛCDM (Gott 2005; Sheth 2003). Hierarchical gravitational collapse from Gaussian initial conditions should produce more isotropic structures, not extremely elongated sheet-like configurations.
The standard model assumes structures form by gravitational collapse from approximately Gaussian initial perturbations. Sheet-like geometry with high length-to-width aspect ratio implies one or two preferred directions in the initial conditions, which the model has no clean source for. Collapse should proceed quasi-isotropically, not preferentially in two dimensions.
SCT replaces the hot-dense-center with a superluminal collision and the thermalized debris field. From this single change, walls are direct geometric products of cascade collisions where one parent pocket impacts another with finite impact parameter at the relevant scale (P22, P34). Cascade-pocket pairs colliding near head-on at large scales produce wall geometry with thickness set by the smaller pocket's extent: W ∝ R_min (P33). The high aspect ratio is the natural cascade signature, not an artifact of fine-tuned initial conditions.
The CfA2 Great Wall thickness corresponds to cascade-stage geometry at the few-hundred-Mpc scale: head-on collisions between cascade fragments of comparable size produce the observed sheet morphology with the characteristic 10 to 20 Mpc thickness reflecting the smaller fragment's self-gravity scale. Multi-stage cascade dynamics (P36, P37, P38) sets the relevant cascade stage that produces walls at this scale; longer walls come from earlier cascade stages with larger v_rel and parent-pocket separations.
The CfA2 Great Wall belongs to the same cascade-deposited large-scale-anomalous-structure population (P55) as the Sloan Great Wall (recid 99), the Hercules-Corona Borealis Wall (recid 100), the Big Ring (recid 85), and the Giant Arc. The same M4 framework that produces all of these gigaparsec features at predictable scales produces the CfA2 Great Wall thickness. There is no need to invoke special initial conditions or modified collapse physics.
If precision Euclid + DESI cosmic-web morphology surveys find the wall-thickness distribution scales according to standard hierarchical collapse predictions (W ∝ M^(1/3) with no cascade-stream-collision signature), the M4 cascade-collision explanation is refuted. The signature SCT prediction is W set by the smaller cascade-fragment scale, with the wall population belonging to a discrete cascade-stage hierarchy.