Managerial positions are not classes. You are confusing the Marxist understanding of class, which is based on ownership of the means of production and distribution, with a more anarchist association of class with hierarchy. Administrative labor is proletarian in nature if the administrator owns just as much as the rest of the class. Their increased power is a privledge that comes from the working class as a whole, and can be taken away in the form of recall elections. This is how it generally works in socialist countries.