Special attention has been paid to the atomic mixing formed between the constituent elements as well as their oxidation resistance properties. To do so, our analysis introduced and applied two key metrics: the Cluster Ratio and the Oxide Ratio. The Cluster Ratio effectively quantified the degree of atomic-level mixing across various HEA samples. We observed a clear trend of increasing CR with the number of alloying elements, indicating improved atomic mixing in more complex alloys. The HEA Mix sample, showing no phase segregation, exhibited the highest CR, validating its superior atomic homogeneity compared to the HEA Seg sample, which displayed elemental segregation.