I realize I expanded the scope by bringing Engels' "On Authority" into the conversation. I want to remain focused on Lenin's vanguard party as an implementation of the "dictatorship of the prolitariat". I agree that Lenin's ideas were informed by the writings of Marx.

Marx's "dictatorship of the prolitariat" could be implemented as a vanguard party as per Lenin. Lenin's iteration could be construed as accurate to Marx's definition.

However, Marx also referred to the Paris Commune as a "dictatorship of the prolitariat" even without a vanguard party. Therefore my qualm, similar to the original comment, is that Lenin's vanguard party is a method to extract rents from the prolitariat.