Bogus metrics will distract the self-evaluation of the teachers. Further, being paid bonuses or being fired based on bogus metrics makes you afraid of mistakes

Bogus metrics will distract the self-evaluation of the teachers. Further, being paid bonuses or being fired based on bogus metrics makes you afraid of mistakes as opposed to feeling trusted in experimenting with improvements and makes you try to optimise for those metrics as opposed to thinking how to best perform your work. Natural selection and annual culling of the herd does not happen in Finnish schools - I think the OP was saying this of other systems. Selection does happen when you take the entrance exam for teacher training though.