Luminosity distributions of observed sources (red lines) and sources in the theoretical population (light blue lines) in six different galaxies. The observed SMC and LMC sources are taken from Davies et al. (2018); for the remaining sources the luminosities are derived in this work. At the right side of each panel, we list the number of observed and model population sources with log(L/L_⊙) > 5.6, along with the associated Poisson probability of having this many or fewer observed sources (given the theoretically predicted number).