Resonant Cavity Enhanced Photodetectors (RCE-PDs) are widely considered as a promising solution for high-speed photodetection, as they effectively overcome the inherent trade-off between transit-time-limited bandwidth and quantum efficiency because of the multipaths of the incident light due to the presence of the Fabry-Pérot cavity that the photodetector is inserted in. In the case of Resonant Cavity Enhanced Avalanche Photodetectors (RCE-APDs), the photocurrent is further enhanced through the avalanche multiplication gain. In these photodetectors, the influences of tolerances in the dimensions of the multiplication, absorption, and charge layers on the electron ionization coefficients, multiplication gain, and overall device performance are investigated. This paper presents a stochastic analysis of the multiplication gain in RCE-separated absorption multiplication-APDs (RCE-SAM-APD), that is based on Monte Carlo simulations and on the frequency response of the photodetector.