Marx wasn't the first, and he wasn't the last to argue for a community/worker owned and operated economic system. He's just the best known. He might have co-written written a manifesto, but had he not another would very likely have. It was a long time coming. But that's really besides my point.
Importantly, Marx did not advocate for a totalitarian political regime. That's a big deal, because that's a defining element of Stalinism. Marx didn't cause that aspect; the aspect that people actually detest. Stalin did. His military underlings did.
I'll say it again, because it's very misunderstood, generally speaking: Marx did not advocate totalitarianism.
Another underlying point is that violent men come from many places, and given the conditions of early 20th century Russia, I would argue the Russians would have had their violent revolution and totalitarian regime, Marxism or not. Like the French had happen to them. Violence begets violence, and Russia, under their monarchy, was an ugly place and had been for a very long time.
So, Stalin was probably coming no matter what, I hate to say. And he was a totalitarian, unlike Marx.
Interesting side note: Stalin was a darling in the U.S. before we demonized him after we were done with the War. Kind of like Saddam Hussein.