While a model of excellent performance is achievable for a certain range of tasks, many of the most important components of company survival can not be simulated in a test. In a very real way, assessment produces an increasingly homogenous output. It's useful to understand that assessment can be seen as the operational opposite of diversity. Assessment is a way to minimize difference. The broad use of assessment carries the risk of removing the foundation of innovation in an organization.
Creativity comes from unlikely juxtapositions.
The best way to maximize differences is to mix ages, cultures and disciplines. The counterpoint is diversity. Juxtaposition of truly different people opens the doors to creativity, to active testing and exploration of values, methods, styles, goals. Ferment and conflict lead to a tribe that is more responsive to change, strange new ideas, and opportunity. I've yet to see assessment tools that promote diversity and help me find quirky troublemakers to spice up my organizational soup.