Despite pronounced research on hard carbon (HC) anode materials for sodium-ion batteries (SIB), particularly the impact of particle morphology on electrode microstructure poses open questions regarding ionic as well as electrical transport or sodium metal plating. This study systematically compares two hard carbons, one representing a nonspherical particle morphology (HC-Ref) and the other representing a spherical particle morphology (HC-Sph-10:90). Industrially relevant loadings were investigated across powder, electrode, half-cell, and full-cell configurations. The analysis of powder and electrode microstructure revealed that spherical particles exhibited superior packing efficiency, leading to higher electrode densities, whereas nonspherical particles retained electrode porosity upon calendaring, thereby enhancing ionic transport. The formation of multipoint contacts was identified to enhance conductive pathways. The electrochemical characterization revealed a clear trade-off between the dense packing and transport capability of the anode. This trade-off translated into three-electrode full cells, where morphology-related polarization affected the potential-defined onset of sodium metal plating. Sodium metal plating is therefore governed by operating conditions like current density and voltage window, while the electrode structure determines the underlying transport limitations and thus the plating susceptibility. Consequently, electrode microstructure is presented as a critical design parameter, together with design guidelines for the optimization of hard carbon anodes for high-energy and plating-resistant SIBs.