I get your point but Stalin was not an intellectual and has never been considered one, not even by the Intelligentsia and much less by western intellectuals. It's not a case of good or bad, the man simply wasn't very bright. I welcome you to read any of his writings, he was a historicist and a refuter of science (Lysenkoism) much like his peers.

To understand Stalin's "success", you must first understand Russia and its history.

The idea that we can just profile Stalin/Hitler and what not, then try to find people that fit that profile to keep them away from power is at best naive and at worst dangerous.