And I do believe that no one wants to participate in a bounty where the manager is Junior (even if there is a Hero behing it) because he will not be responsible enough.
Judging by their rank to conclude how they perform bounty management is not what I usually do though. Even Legendary/Hero/Senior ranked managers are sometimes a pain in the ass. Ridiculously slow to update and responds to participants inquiry and so on. For example, bountyportal (run by a Legendary manager) is very unresponsive, has a lot of problems in the platform, etc. See their group for yourself.
I'd rather see how well they perform their works, regardless of their ranks. Sometimes an ICO starts the bounty by themselves using Copper Membership, and they did well managing their bounty.