Let's do some more math. Stalin, according to Kruschev who had every incentive to exaggerate, killed some 30 million people over 40-odd years. Let's assume he didn't know about them all and call it 50 million.
The fossil industry alone, according to the WHO kills 9 million innocent people  a year. So just one capitalist industry kills as many people every 6 years as Stalin did in his entire reign of terror.
That number also do not include workers killed by that industry (everything from black lung to mining accidents). Add those (as you ought to) and this single capitalist industry kills more people every three years than Stalin did.
I don't believe there is such a thing as a lesser evil. All evil is absolute evil. 
But those who do surely cannot objectively claim that Stalin isn't mathematically the lesser evil here. In over a century fossil alone has beaten his death toll a hundred times over. And it's not the deadliest industry there i (construction). Imagine counting all industries