Comparison of the redshift distributions, source number counts, SFRDs, and ratio of submillimeter-bright SFRDs to cosmic SFRDs using the H13 relation for the three fiducial FLAMINGO simulations with different resolutions and box sizes. Simulations L1_m8, L1_m9, and L2p8_m9 are respectively shown with blue, orange, and green colors. The gray symbols in the top-right panel are observational data. The small bars at the bottom of top-left panel indicate the medians of the respective distributions. In the bottom-left panel, dotted curves are the cosmic SFRDs, solid curves are submillimeter-bright SFRDs, and the black dotted curve is the Madau & Dickinson (2014) fit to observations. The remarkable overlap between L1_m9 and L2p8_m9 shows that a 1 cGpc box side length is large enough for modeling the (sub)millimeter galaxy population. The top-right panel shows that higher resolution improves fainter end source number counts.