Synchrotron emission along the Galactic plane is far more depolarized than Faraday rotation and turbulence models predict, with beam and depth effects modeled and insufficient (Planck 2016; Pasetto 2018). The residual demands either turbulence beyond MHD expectations or a Faraday-thick component the templates do not contain: structure the uniform models miss.
The models build the Galactic field by dynamo action and stir it with supernova-driven turbulence, yielding a statistically uniform random component whose depolarization is calculable. A residual beyond that calculation means the field carries organized structure at scales the dynamo-plus-turbulence picture does not generate.
SCT gives the magnetized medium the structure the models miss, by inheritance. The Galaxy's magnetic topology is not built from scratch by the dynamo: magnetic configurations are among the collective properties pockets carry and pass down (P12, P25), so the field threading the plane descends from the deposited structure's topology, reorganized but not erased by subsequent dynamo action. An inherited field carries organized small-scale structure, folds, reversals, and Faraday-thick filaments laid down by the deposit's geometry, that statistically uniform turbulence models neither produce nor anticipate, and integrating across that structure along the plane's long sightlines depolarizes precisely as observed.
The ionized-gas half rides the same inheritance: the heterogeneous deposited medium (P25, P28) supplies Faraday-thick pockets of magnetized ionized gas outside the template inventory, the same population-level diversity behind the plane's joint foreground failures (recid 202) and the free-free anomalies (recid 205). The registered expectation is structural: the depolarization residual should correlate spatially with the other foreground residuals and with the inherited large-scale field architecture, one underlying topology read through several instruments, rather than scattering as independent modeling noise. The inheritance context is in Paper 4, From Chaos To Collisothermal Cosmogenesis, with the pocket-property framework in Paper 1, From Chaos to Convergent Foundations.
Keystone economy: P25 supplies the inherited topology, P12 licenses fields as heritable properties. The missing polarization is the field's history showing through.
The registered kill: if next-generation polarization surveys, with C-BASS-class low-frequency anchoring, resolve the residual depolarization into ordinary turbulence at MHD-consistent levels once the field model is refined, the inherited topology is unnecessary. SCT separately requires the residual structure to correlate with the other foreground anomalies; a depolarization map statistically independent of the AME and synchrotron-index residuals would break the one-topology reading.