Not all anarchism is equal, and I'm not sure there is any validity to "scientific socialism" as a notion. Most schools of anarchism are taken from real struggle - the most rigorous one being syndicalism, which is the use of strong unions as the vehicle for class warfare. I don't think that most schools of anarchism are utopian or "scientific" so much as they are practical.
"Practical" Anarchism? Judging by their historical record of success (or rather, the lack thereof), isn't that almost a contradiction in terms?
And there
is validity to the notion of "scientific socialism". This is why Marxism has taken over from every other form of Socialism and Communism from the late 19th century to the present day. Nobody describes themselves today as a 'Fourierist' or an 'Owenite', with good reason - Marx comprehensively refuted their ideologies, and demonstrated the intellectual
and practical superiority of a Socialism based on rigorous economic and political analysis rather than Utopian daydreaming. And while the ideology of Marx has had, and is still having to this day, a tremendous impact on fields of thought as varied as literary analysis, film studies, semiology, psychology, sociology, etc, the ideology of Bakunin has had almost zero influence on any serious thinker. Marxism is both intellectually sophisticated and profoundly practical, while Anarchism is neither.
"Politics is the art of looking for trouble, finding it everywhere, diagnosing it incorrectly and applying the wrong remedies." - Marx (Groucho)