I think that you might be able to feature some interesting thoughts on the issue. I would think that one of the most primary points that need to be made is the idea that the Russian Revolution, and by extension, Communist nations in Europe fundamentally challenged Marx's theoretical idea of the stages of development. Marx was a firm advocate of the historical and social dialectic in which nations and their economies must undergo change in order to embrace the next change. One of the most critical evolutions in this process is the idea of moving from a capitalistic, industrialist venture to a socialistic one, a transformation from a private form of wealth ownership to a public one. This was never seen in Russia, a primarily agrarian setting that never endured mass industrialization. Both Russia and the European nations that were compelled to follow its example challenged Marx's theory and fundamentally changed it in missing this critical step of the economic and historical dialectic. What Trotsky would point out later as "deformed workers' states" would mar the Russian and Eastern European examples of communism in that one ruling elite was swapped for another one. An economic group that controls power and society was supplanted by a political one. Marx's true notion of public ownership of power was still being denied, and I think that this might be one way to suggest that Russian and European nations changed Marx's theory.