Vetting 30 to 50 suppliers before narrowing down

Trying to figure out how many suppliers is the right number for vetting suppliers in China before committing to a manufacturer. The supplier vetting funnel I've been running through kanary solutions pulled in about 40 candidates I never would have found through Alibaba alone, which narrowed down to three after sample QC. Wondering if there's a point of diminishing returns where you're just adding noise to the decision.

I've heard everything from three to fifty depending on who you ask, and the answer seems to depend a lot on whether the product is custom formulation or off the shelf. Of my own shortlist, half didn't respond past the first message, two sent samples clearly not from the same factory as what they claimed, and one was excellent but had a 90 day lead time that doesn't work for my launch window.

Curious how much further down the list other people go before settling.