You have the Cause and Effect backwards.
All you are saying is that to maintain society as it presently exists, a government is needed.
No anarchist would disagree; it goes without saying that every aspect of our society presupposes the existence of a government.
If it requires coercion and theft to build the railroads, then perhaps we shouldn't have built railroads. Stated differently, if it requires a government to have welfare or social security, then perhaps we shouldn't have welfare or social security.
In short, you are simply saying there is no way to maintain prison society without prison guards; you assume at the outset that the prison society is something that must be saved at any cost.