Left-Communists are irrelevant so long as they refuse to actually organize the working-class. In any revolutionary situation they'd be ancillary to Anarchists and Trots.
Trots see revolutions everywhere unless there are "Stalinist" parties about, then it's a question of revolutions about to be "sabotaged" by them. In Spain and France in the 30's they called for splitting the popular fronts through civil war. In the early 40's in Albania ultra-left and Trotskyist elements called for a "Soviet Albania" and opposed the unity of all anti-fascist forces.
What's funny is that at the same time Trots tend to align themselves with reformists, e.g. today in Greece with SYRIZA, three decades ago in Britain with Labour, and there are plenty of Canadian Trots who insist that the NDP can be "moved to the left" through the practice of "entryism."
Unity is achieved through struggle. What is needed is not a unity of the Marxist-Leninists with petty-bourgeois tendencies that are themselves of scant importance, but with the working-class.