Randy, of course, has succinctly framed an issue which has been the underlying demon in countless threads over many years here in the Cove: "Many organizations have chosen the "easy CYA [cover your ASSets]" path by mandating the supply chain MUST have formal certification from a legitimate issuer of certification to a Standard.
The issue being that there can always be an "exception." The exception can be what Randy alludes to (a formally certified supplier who makes dreck.) The other exception is the self-assured supplier who says to would-be buyers: "I'm great at what I do. Some big buyers have checked me out, liked what they saw, and buy from me even though I don't have a formal certification to a Standard. Buy from me or not!"
My experience with the issue parallels Randy's. When my company was in the supply chain for aerospace and medical devices, we did NOT blindly accept a certificate for any supplier making critical components and checked such suppliers to our own requirements. Similarly, we stood tall and backed some uncertified suppliers to the companies above us in the supply chain which DID HAVE the "easy CYA [cover your ASSets]" path by mandating the supply chain MUST have formal certification from a legitimate issuer of certification to a Standard.
If we lost a contract because of that, we just put on our big boy underwear and moved on. I can truthfully say I slept better at night.
So, to the Original Poster, Danny K, my advice is simply:
MAKE YOUR OWN DECISION
(don't put all your reliance on which company to add to your supply chain because of any third party's statement.)
As for me - we [as an organization] did NOT have the easy CYA clause in our purchase agreements.