You're right, but to reason about a hypothetical scenario, we've got to make assumptions. Identifying under-performers with perfect precision is my assumption

You're right, but to reason about a hypothetical scenario, we've got to make assumptions. Identifying under-performers with perfect precision is my assumption of a spherical cow! https://en.wikipedia.org/wiki/Spherical_cow https://en.wikipedia.org/wiki/Spherical_cow