How about reading them all and using dialectics and historical materialism as a framework to understand the context of their ideas?

Marx and Engels envisioned the revolution would come first from the most advanced countries, and this dominated Marxist thinking in the late 19th century. Lenin broke from this idea comprehending by his study related to imperialism. He saw backwards Russia not as a feudal state but one that already begun in its capitalist development. He understood that capitalism wouldn't develop in the same way in the imperial core and in the periphery and this is a core pillar on Soviet thinking and foreign policy. In Russia, he promoted an alliance between the peasants and workers of Russian urban centers to sponsor the revolution. Mao took a step further and positioned the peasantry as the main revolutionary class in China, due to the agrarian configuration of the country. After the revolution, Mao combined Soviet planning and agrarian communes but failed to industrialize the country, even though it created on the communes and industrial base. Deng integrated China in the international system and adopted liberal reforms to finally industrialize the country, but still maintained CPC power. Other CPC members (which I don't know the names) softened Deng stance on market reforms to avoid the bad effects of a shock therapy and this opened way to a more experimental approach to create the Chinese industry we see today.

So basically every socialist leader acted on the contradictions of the previous ones and dialectically transformed one model into another. Basically different material conditions and different contradictions gave rise to new higher forms. And that is the beauty of dialectics and historical materialism, it does not enforce a static theory, but a dynamic one that is constantly changing.