A thought for G7+ folks: before 2012, managers could either put raise increase dollars into base pay or they could put it into EB target. Since EB target gets 3X multiplied, it made more sense to do that. After 2012, they changed the rule so EB dollars were 3X base pay dollars, and EB targets were not increased as quickly.
This means that older employees, compared to newer employees in the same grade, had a much higher EB target, which would lead to higher pay. Newer employees would start with higher base pay to compensate, but the EB targets were still high for older employees. To keep total comp the same, managers would be more inclined to give lower stock ratings for older employees, which biases them more towards the SSL4 layoffs.