We should not rely on the rank of bitcointalk account only, but consider other things as well.
We don't know when the hero/legendary member is a hacked account or not, so it won't give us the guarantee of good project.
Sometimes new project decide to announce with their own account, usually newbie rank account because they just create the account.
Relying on the rank is only one criterion to consider, it isn't very important but has certain influence. Some projects are managed by newbie , they are also very successful, but most of them fail or scam. Therefore, big projects still need the hero/legendary members to manage them, only increasing trust, we still need to research carefully before investing.