[vog]

Exactly. And since that piece is missing, I wouldn't describe that team "great", but at most "good" or "promising". Maybe "promising but incomplete" is the best description.

As a team leader (or manager) one of your most important tasks is to choose the members and to get them together. If you didn't fill in all needed roles, you haven't finished that task.

(I wanted to add a Tom DeMarco quote here, but I don't recall which of his books described how to build a software development team - perhaps "The Deadline"?)