two-atom system, as encoded in the eigenstates of the dimensionless matrix $G$, whose elements $G_{12}$ were introduced in [Eq. \[eq:CDS\_input-output\_eq\_single\_mode2\]]{}. When $\rho_{12}\ll 1$, $G$ is dominated by its off-diagonal components $G_{12}=G_{21}$, and in particular, by the purely real $1/\rho_{12}^3$ near-field term (which we denote by $G_{12}^{\text{near}}$). Specifically, in spherical coordinates $\boldsymbol \rho_{ij} \equiv \rho_{ij} (\cos \theta, \sin \theta \sin \phi, \sin \theta \cos \phi)$, $G_{ij}^{\text{near}}= 3(-1+3\cos^2 \theta)/(4\rho_{ij}^3) $. This describes the strong, coherent, near-field coupling between the two dipoles. This produces symmetric and anti-symmetric eigenstates whose dimensionless normal mode frequencies (real parts of the eigenvalues) are shifted as $\omega_{\pm}\approx \pm G_{12}^{\text{near}}$, and align with the resonant peaks seen in [Fig. \[fig:RG\_plots\]]{}-a. The linewidths (given by the imaginary parts of the eigenvalues) also are modified as $\Gamma_{+}\approx 2$ and $\Gamma_{-}\approx \rho_{12}^2$, which is simply the two-atom limit of the famous Dicke superradiance model [@Gross1982Superradiance:Emission]. The key insight is that due to the large splitting, the total response in [Fig. \[fig:RG\_plots\]]{}-a appears as two well-separated Lorentzians. Although this arose from the strong interaction of identical atoms, such a spectrum would *also arise* from two, inhomogeneous and *non-interacting* atoms, which were simply assigned these resonance frequencies and linewidths to start. This concept is 