A sensitivity analysis of the Mantel coefficient corresponding to a 2.5σ and 5σ anomaly, as a function of the number of planets observed. Positions and compositions of planets are chosen as in our model (see Section 2). We find that the sensitivity of the Mantel coefficient to the number of planets decreases exponentially, and 1000 planets seems like a reasonable choice to reflect the balance of the challenge of realistically observing planets, with the need for those planets to exhibit potentially small correlations in composition–position space. The exact shape of this plot will vary by model parameters, but it is especially dependent on the distribution of planet compositions and positions (e.g., planets being evenly distributed in composition or position space, vs. extremely heterogeneous; not shown).