How is a small company realistically going to test if someone is worth hiring or not.

we got into this stupid market because we spent decades neglecting training. When you don't train for what you need, you don't get good at identifying what skills you really need in order to succeed.

So this question is already too far gone. If someone has most skills but is missing one: train them for it. Even if the training is as informal as "give them a few weeks in a low stakes environment to work on less valuable (but less risky) work.