Amazon partnering with existing pharmacies seems like a very plausible step to me. Amazon storing inventory from those pharmacies in a single location also sounds like a plausible step to me. And then that's comingling that requires me to trust the absolute worst partner. With good reason to worry that these invisible companies might not have the best standards.
Which step do you think isn't plausible?
And I'm not saying I won't trust it, I'm saying I'd have to research it more and keep extra vigilant for any changes.