belief by national that it is more turbulent for leaders to have to step down rather than to face issues like this

This is rather revealing of the nature of "leadership". You can either define it rigorously which means having specific roles that have expertise and commitment requirements, don't always overlap, and don't always rank themselves in a chain of command or pecking order, or you can allow the propensity for domination and deference to emerge, and "leader" just ends up becoming "that person who is above all these followers/members" and voilà, you have internally replicated a class dynamic.

A party/movement with a quorum of Parliamentarians, a quorum of Mentors, a quorum of Strategists, a quorum of Spokespeople, a quorum of Taskmasters, and a quorum of (diplomats, recruiters, negotiators, whatever you want to call external relations that's not just communication) is going to accomplish many things at once. It will not have a strong of a leader/follower dichotomy, it will allow more people to be involved in distinguished roles, it will allow people in each role to specialize better and not stretch themselves thin, it will limit the potential benefit of infiltration, it will make it a lot harder to try to blackmail or compromise or decapitate the leadership, and it will make the organization "fairer" to the rank and file while still keeping confidentiality.

You can still have a vanguard party with this model. You can possibly even have a DemCent party with this model too.