Simulated alignment precision of the ephemeris frame onto the Gaia and VLBI reference frames as a function of the number of pulsars (blue filled circles for Gaia MSPs, blue filled squares for VLBI MSPs, red inverted triangles for Gaia non-MSPs, and red filled triangles for VLBI non-MSPs). The X-axis at the bottom corresponds to the number of MSPs, while the X-axis at the top corresponds to the number of non-MSPs.