Size Consistency is derived directly from the Size Consistency Metric as follows.
HIGH: Size Consistency Metric is less than 6
MEDIUM: Size Consistency Metric is between 6 and 21
LOW: Size Consistency Metric is greater than 21
The breakpoints of 6 and 21 are static following a 20-60-20 rule. That is, roughly 60% of portfolios will be labeled as Medium, and 20% each as Low and High.