The state is a power structure. I don’t become a corporation when I get a job at McDonalds.
So you understand how labour and management are not the same thing, right? Police have the authority of the state. They literally rule us. That is not labour.
Labour is the class that produces value. Police don’t produce value, they implement the will of the state by doing violence against citizen of that same state. Labour theory is just not meaningful when applied to the police.