If there is one thing that is absolutely guaranteed when working with a team, if multiple people are made accountable to an outcome it is unlikely to happen. It is the ultimate game of passing the buck, which usually ends with a triumphant finger pointing.
Whenever a specific outcome is needed, make one person (and only one person) accountable to the outcome. If it doesn’t happen, they are the one to face the consequences. If they succeed, they receive the recognition.
Of course, one person may be not be the adequate staffing to complete the goal at hand. The other people are responsible. They all must get their roles, and report to the one who is accountable. So while many can be responsible for a project, only ever make one accountable.