Marx is difficult I think because of his background and who he was and who he intended his works to be communicated too. He was purely an academic speaking in academic language writing, in most cases for other academics. Thats why if you read his personal letters, he seems to speak more like a human would, and if you read his publications intended for reading by everyone (like the communist manifesto) he does engage in allegory and imagantive writing to accent his points (...there is a spectre haunting)

Meanwhile Lenin had to be able to communicate with the educated russian class, but also the rank and file of the revolutionary army as well as the Russian serf class; he knew most of his writing had to be understood on the terms of the less educated as a whole class but intended to educate everyone to the level that they could understand him removed from western academic language, to his benefit I think; detatching from liberal academic language is a revolutionary thing in itself.