<p>Asymmetric multi-oscillator locally resonant phononic crystals (AMLRPCs) can enrich subwavelength resonances, but the specific role of layout asymmetry remains unclear when resonator multiplicity and oscillator spacing also change the bandgap response. In this study, a conventional single-oscillator LRPC and six five-oscillator AMLRPC layouts are compared under a constant total scatterer area. A comprehensive asymmetry factor combining centroid offset and inertia anisotropy is introduced, and dispersion curves, modal participation factors, finite-array frequency responses, and deterministic perturbations are analyzed. The results show that splitting one scatterer into multiple oscillators is the primary source of bandgap multiplication, whereas increasing layout asymmetry mainly promotes modal splitting from cooperative translational resonance to eccentric rotational resonance. Consequently, stronger asymmetry increases the number of bandgaps but does not necessarily enlarge the total bandwidth or improve finite-array attenuation depth. Symmetric or weakly asymmetric layouts provide stronger average attenuation and better robustness than the strongly asymmetric inverted-T layout, while oscillator spacing offers an additional tuning dimension independent of global asymmetry. These results suggest that controlled asymmetry, rather than maximal asymmetry, is more effective for balancing bandgap multiplicity, low-frequency coverage, attenuation depth, and robustness in AMLRPC design.</p>