The CfA2 Great Wall is a coherent sheet of superclusters roughly 750 Mly across, pressing against the maximum size hierarchical growth can assemble in the age of the universe, with the Sloan and Hercules-Corona Borealis walls sailing past the same ceiling (Gott 2005; Einasto 2011). Gravity cannot correlate matter farther than it has had time to act.
The model builds all structure by gravitational assembly from Gaussian initial conditions, so coherence has a speed limit and a size ceiling. A wall whose parts hang together across distances light has barely crossed since recombination has no permitted construction method, leaving statistical-fluke arguments that weaken with every deeper survey.
SCT removes the speed limit by removing the assembly. Walls are direct geometric products of near-head-on cascade collisions: the intersection front engulfs the overlap volume before any internal signal can cross it (P22), so the deposited structure is coherent from its first moment, over whatever extent the colliding pockets spanned. Nothing had to be assembled across the wall's length, which is why its coherence does not strain any growth rate; the coherence was a property of the event, not an achievement of gravity afterward.
The cascade hierarchy then organizes the wall population: earlier, larger stages deposit the giant walls, capped at the first-stage characteristic scale Λ_max ≈ 2 × R_pocket ≈ 5 Gpc (P55), while later daughter stages (P36, P37) deposit the smaller members like CfA2. The Great Wall, the Sloan Great Wall, and the Hercules-Corona Borealis Wall are one family read at three cascade stages, sharing the ring-and-filament morphology of shock-compressed shells that also delivers the Big Ring and Giant Arc (recid 85). What ΛCDM treats as a stack of separate impossibilities, SCT treats as the expected size spectrum of one mechanism. The deposition physics is in Paper 1, From Chaos to Convergent Foundations, with the structure-seeding mechanics in Paper 4, From Chaos To Collisothermal Cosmogenesis.
Keystone economy: P22 supplies the instantaneous coherence, P33 and P34 the geometry, P55 the size cap. The wall is not too big for the universe; it is exactly the size of the event that made it.
DESI and Euclid wall censuses carry the kill: if the population of coherent walls terminates at the hierarchical-growth ceiling, with the giant members dissolving into pattern-recognition artifacts under deeper sampling and no structures persisting toward the Λ_max ≈ 5 Gpc scale, the deposition origin is refuted. SCT requires the giant tail to be real and to cap near the first-stage pocket scale; walls beyond ~5 Gpc would equally break the parent-pocket hierarchy.