'The vanguard' IS the workers driving the revolution. The vanguard party is the most advanced section of the workers, the workers that have read the most theory, have the most experience and have the most developed skills of organization. Saying they should just "act as advisors" is saying they should wait for the workers to spontaneously develop another different organization for them to give suggestions to - but then doesn't that organization just become the new vanguard, which should also stand aside and act as advisor instead of leading?

Though having just said that, at the moment of revolutionary potential, how is "taking the role of advisors" any different to "leading"? The Bolsheviks didn't coerce the workers into following them (indeed, how exactly could they have done?), they didn't grab a magic crown that assigned them the position of "leaders of the revolution" and all the other workers just had to fall in line - the workers gave their support to the Bolsheviks, chose to listen to their ideas and carry out their tactics, because they had proved through their achievements that they were the best and most capable party, in terms of bringing the changes that the workers wanted to fruition.

The conditions of bourgeoise society caused the formation of various organizations claiming to fight for the workers. Out of all these different possible options, only the Bolsheviks gained the support of the mass of workers - and they did so by having the most advanced theories, combined with the most experience of organizing, resulting in their deployment of successful tactics (all of which Trotsky himself was involved in!) So, in retrospect, out of all the other parties that fell by the wayside, we can say they were the vanguard party.

Now, that all said, I can see how there could be a misapprehension of what the vanguard is, mainly because of the state of the current Western left. People talking about and concerned with the "dangers of vanguardism" are themselves most likely Westerners that haven't read theory or history, and probably still believe Western lies about communist states and communism in general. For such people, the only communists (and probably leftists of any kind) they will have interacted with will be intellectuals and academics, so their understanding will be skewed - they likely assume that 'the vanguard party' simply appears fully formed out of communist professors and talking heads and then 'descends' to take control of the workers movement, rather than arising from it organically. This is compounded by the fact that, in the west, the workers themselves are likely to be hostile to communist positions because of the advantages they enjoy from imperialism. So to them, the idea of 'vanguard' and 'workers' being separate entities is natural.

But fundamentally, it infantilizes and steals the subjectivity the workers - a very common problem in the Western and 'New' Left, exemplified by George Orwell's Animal Farm for instance - implying that the vanguard should "choose" to stand aside and "let" the workers do what they want as if the vanguard could stop them! All the vanguard CAN do is point out how the workers can get what they want, and present a compelling enough, evidenced enough argument for their solution that the worker filled with revolutionary zeal, the active burning need to tear down an unjust world, will agree with them.

This ended up a little long because I haven't got time to make it shorter, but I hope I got the point across without too much repetition. For more reading about the pitfalls of Trotskyism, I recommend this short article as well as the book it's based on.