Building on the alternating-waveguide closed-mechanical-subsystem architecture introduced in [ , 041027 (2018)], we develop a diamond phononic network that overcomes the coupling-hierarchy bottleneck in the implementation analyzed there. Beyond replacing NV centers with SiV centers, we independently engineer the two relevant couplings: localized defect modes and strong SiV orbital–strain interaction enhance the spin–phonon coupling $G$, whereas cavity–waveguide engineering suppresses the cavity–waveguide coupling $g$. The resulting coupling hierarchy reverses that found in earlier physical implementations of closed-mechanical-subsystem networks and places the system in the $G\gg g$ regime required for direct state transfer. This hierarchy reversal qualitatively changes the appropriate control strategy from bichromatic Mlmer–Srensen driving to a simple direct triple swap. Within our model, the resulting protocol enables state transfer with a fidelity of $0.999$ on a microsecond timescale and remains robust against mechanical dissipation, spin dephasing, and finite thermal occupation. Our results establish a distinct route for scalable solid-state phononic quantum networks.