That's the main problem with this ISP approach: indiscriminate removal of successful employees with ones with legit performance issues.
Might as well have chosen shoe size or hair length as ISP criteria.
"Unfortunately it was the other way around. ISP employees that ranked above the 50% line but got SL4 because of years in same grade or FLM discretion got the same treatment as people with IR, or written warning, or in a CAP :-("