Yes, this is a must. As a rule, they hey around this situation as follows: once the initiators of setting up a cooperative have come to mutual agreement, they choose three people who will act as founders and who will issue powers of attorney for registration and sign registration documents. After registering the cooperative has been completed, these three founders accept the rest of the members of the cooperative. At the same time, the first three people have the same rights as all other accepted members, who were later added.