  Traditional large-scale models of reionization usually employ simple
deterministic relations between halo mass and luminosity to predict how
reionization proceeds. We here examine the impact on modelling reionization of
using more detailed models for the ionizing sources as identified within the
$100~{\rm Mpc/h}$ cosmological hydrodynamic simulation {\sc Simba}, coupled
with post-processed radiative transfer. Comparing with simple (one-to-one)
models, the main difference of using {\sc Simba} sources is the scatter in the
relation between dark matter halos and star formation, and hence ionizing
emissivity. We find that, at the power spectrum level, the ionization
morphology remains mostly unchanged, regardless of the variability in the
number of sources or escape fraction. In particular, the power spectrum shape
remains unaffected and its amplitude changes slightly by less than 5-10\%,
throughout reionization, depending on the scale and neutral fraction. Our
results show that simplified models of ionizing sources remain viable to
efficiently model the structure of reionization on cosmological scales,
although the precise progress of reionization requires accounting for the
scatter induced by astrophysical effects.
