The latter, as it gives credence to the former. A non-paranoid Stalin would be just as unscrupulous to rise in the Soviet system (think someone more like Lenin, in all probability, or maybe a Trotsky-type with a silver tongue *and* the political slipperiness of a Borgia) and would probably be more dangerous by making his scapegoating actually plausible.
Okay, would he still want to kill someone like Tuckavesky in this timeline though? Or would losing his paranoia make him more pragmatic about certain people?