No one blatantly claims authority over the community and even if they did, it is up to everyone's personal decision to follow them which I'd assume they wouldn't give any shits about.
Never even heard of Nakura, who is that?
I only see Ayanavi when we talk about the leader of Dollars, at least she is the one in everyone's back of mind, for those who knew about her charisma and her great influence. She knew and everyone knew, the community will follow her lead if she ever decides to take that so-called 'leader' title.
There will never be another figure like Navi ever again, she reached the impossible to get and be respected by everyone in the community, no exceptions.