The ESA F2 ARRAKIHS mission will map a volume-limited and mass-limited sample of Milky-Way-type galaxies in the nearby Universe down to an unprecedented surface brightness level, with the ultimate goal of constraining the nature of dark matter. The success of the mission strongly depends on detailed predictions of the number and characteristics of stellar streams and satellites in simulations with different dark matter characteristics. We propose to make a major contribution to the science development of the ARRAKIHS mission by (1) optimising a tool to make realistic synthetic ARRAKIHS-like images for simulated galaxies, (2) generating such images for state-of-the-art cosmological simulations with different dark matter characteristics, and (3) defining and improving the figure of merit that guides the optimal ARRAKIHS observing strategy.