Rhetorical strategy by collecting many agreeing individual perspectives to prove something right/wrong

I believe there is a specific rhetorical strategy by using large number of agreeing perspectives to prove the author's point (e.g. Person A said...Person B also stated...Company C explained)

The closest I can think of is testimony but I can't guarantee that as the strategy I'm looking for.

Can anyone clarify? Thanks!

The strategy of using large numbers to demonstrate the truth of a proposition is a fallacy known as "appeal to popularity". In strict terms, merely because ten million people say that, for example, walking under a ladder will bring bad luck, does not mean that it is true.