The leaderboard shows players ranked based on Gladiator Circuit points, but obviously many people have the same number of points. Sometimes multiple players have the same number, but some will be ranked in a higher bracket than the others. Here's an example where, right now, some players with 212 points are in Mysterium III while others with 212 are in Quantum I.

How does Kabam determine the order of players when they have the same GC scores?