Suppose ten qualified jurists discuss a matter: eight support one ruling and two support another. This is a majority view, not unanimous agreement. Eight out of ten is not technical ijma‘ merely because the majority is large.
Consensus becomes relevant when all qualifying jurists of the pertinent era agree and the agreement is established.
Compare:
Majority: some qualified jurists still dissent.
Unanimity: no dissent remains among those counted.
Proof: the claimed agreement must be historically established.
Many supporters is therefore not synonymous with a proven ijma‘.