If you're curious, the main wedge issue that pitted Stalin and Trotsky against one another is the Soviet Union's policy on exporting Marxist revolution

That can't be right. I read a book on this and I was told it was the argument over whether they should attach a dynamo to the old windmill.

they still put up the biggest fights when the concept of working together comes up.

I think this sort of statement is an overreach. I've known a few people who might be described as Trotskyist, and for all their sins they did seem very enthusiastic in their activism. I'd say the problem isn't so much that Trotskyists don't work well together as it is that building movements is hard. You're far more likely to find someone enraptured by Marxist theory who throws themselves into a movement half-cocked and fails, than someone who is well-read and practiced as well as charismatic and sociable to the point that they can build a large successful movement.

Trotsky is more accessible, particularly for academics. But there's no large social movement to interface with such that baby communists can be integrated into the fold. Plus, there's a ton of paranoia (plenty of it justified) such that newer organizations struggle to build steam.

So you've got these hot-blooded activist types pinballing around, desperately looking for an outlet for their energy. And the folks that don't get absorbed by mainstream political establishments or burn out, end up being these cantankerously stubborn zealots that we label "Trots" on impulse.

At some point, the problem of "Trots" is just the problem of organizing writ-large. Its hard. Its time consuming. And it requires the integration of a lot of activists with different perspectives and agendas.