He spoke 1 time of HIS assembly as a kind of assembly distinct from all others. No, Paul speaks of the same church and illustrates it with the concepts of a body, a building and a wife. The church is a coordinated, unified assembly doing as its Head commands just like a body. A list of specific gifts which complement one another in a functional unit. What value to a universal body for someone in Europe to have one gift, another gift possessed by someone in Africa, etc.
Every member is necessary.
He is the authoritative, legislative element. The church completes the Head. A head without a body is incomplete. The head directs. The body acts.