People are more willing to help than it seems, especially if they are able to own their contributions. This sense of attribution is common in all branches of OSS development. Build your communities by empowering your members and leave it wide open for contributions.
This is the “champion”
strategy, where one person leads the effort, but has many other people to help him execute the work. This puts a passionate and motivated person in charge and feeds his desire to make sure everything gets done. Enable him. Offer resources and sponsors. Then focus on what you can do and let your people make sure all the other efforts are receiving attention and being delivered.