Agreed, power should be held by syndicates, ideally with those syndicates/groups/unions/etc working together by sending delegates to a Congress and then abiding by the democratic decisions made by that Congress.

I think deciding who is or isn't the vanguard is something you can only do when you look back at history - you can point at different groups at different times when they were leading the movement, but if you were living through it things might not be clear. It's pointless trying to figure out who the vanguard is right now, instead we should be organizing.