The only thing that you can count on is that Trotskyists have fewer atrocities to rationalise than other Leninists, although Leninists have more to rationalise than other Marxists.

Insofar as we can make any conterfactual historical observations, it's a pretty safe bet that this is only because it was quickly squashed by rival factions. As dirty leftist scum, I observe that opponents of my ideology are absolutely right in calling Trotskyism the most extreme and totalitarian branch of Communism - more ruthless and with more grandiose goals than Stalinism.

(Feel free to downvote for politics.)