Nanowire-based plasmonic lasers are now established as nano-sourcesof coherent radiation, appearing as suitable candidates for integration intonext-generation nanophotonic circuitry. However, compared to their photoniccounterparts, their relatively high losses and large lasing thresholds still pose aburdening constraint on their scalability. In this study, the lasing characteristicsof zinc oxide (ZnO) nanowires on silver (Ag) and aluminum (Al) substrates, op-erating as optically-pumped short-wavelength plasmonic nanolasers, are sys-tematically investigated in combination with the size-dependent performanceof the hybrid cavity. A nanomanipulation-assisted single nanowire optical char-acterization combined with high-throughput photoluminescence spectroscopyenabled the correlation of the lasing characteristics to the metal substrate andthe nanowire diameter. The results evidence that the coupling between exci-tons and surface plasmons is closely tied to the relationship between substratedispersive behavior and cavity diameter. Such coupling dictates the degree towhich the lasing character, be it more plasmonic- or photonic-like, can definethe stimulated emission features and, as a result, the device performance.