You have to have leaders and then do everything in your power to not let them succumb to vanguardism.
I also lean more in to an anarchist style of leadership, but decing everything by quorum can paralyze movements or leave them without a clear message.
“The Vanguard” as you describe it was an ideological justification to describe any and all criticism of the ruling class (and yes, to me, the upper echelons of the USSR were a ruling class) as counterrevolutionary. “The most advanced of the working class” shredded the countries military leader shit on the eve of the second world war not because of existing coups, but out of paranoia. “The vanguard” in the end served only to preserve their own interests.
“The people elected SRs or did not vote majority Bolshevik? What do they know, we are the vanguard, we know whats best, lets ignore the elections and abolish the soviets.”
Thats why i dislike the concept of the Vanguard. Because never turned out the way it was promised and it never will.