Why might Omega Centauri have formed through the merging of earlier star clusters?

The suggestion that Omega Centauri may have formed through the merging of earlier star clusters arises primarily from the unusual chemical diversity observed among its stars.1

While most globular clusters consist of stars with a relatively uniform chemical composition, Omega Centauri contains stars with a wide variety of chemical makeups. This unique characteristic suggests that the cluster may not have originated from a single, uniform cloud of gas, but rather from the amalgamation of multiple, distinct earlier clusters that possessed different chemical properties. This process is considered a smaller-scale version of the "galactic cannibalism" observed in larger systems, where galaxies merge and combine their respective stellar populations.1