In this work, we present a holistic method for evaluating D-A polymer solution state primarily through SAXS experiments supported by scanning electron microscopy (SEM) and atomic force microscopy (AFM) imaging of freeze-dried solutions. To add to the current understanding of conjugated polymer solution state through scattering, we present here several modeling approaches towards understanding D-A polymer scattering and developing a clearer picture of the solution state. We present two models for the scattering profiles, the first of which is based on the contribution of two semiflexible cylinders similar to what has been previously reported but with a pseudo-Voigt peak to capture a lamellar peak feature (2SFC model). More importantly, we develop a second model based on the scattering theory of particle assemblies that explicitly considers hierarchical aggregation of polymer chains into fibril aggregates (FA model). In doing so, we are not only able to fit and extract structural parameters from scattering but also establish the physical basis for the unique features observed in D-A polymer scattering and thereby improve the understanding of conjugated polymer solution state aggregation. In particular, we resolve the origin of the broad high 𝑞 peak that has been intermittently reported in prior works . While it has been speculated to be due to lamellar stacking it has not been clearly explained or modeled so far. In addition, it has not been observed consistently potentially due to limited 𝑞-range, high incoherent background scattering, or its dependence on solvent quality, as we will show. Furthermore, we demonstrate the generality of our fibril aggregation model by fitting a variety of D-A polymer scattering profiles containing the lamellar peak.