There are a number of challenges with ranking problems when uncertainty is high.

There are a number of challenges with ranking problems when uncertainty is high. The top being: You don’t know what you don’t know.

Your list of starting problems may not be the highest ranking problems. Asking customers to rank them anyway is a false positive. Most customers won’t volunteer the right list because either they don’t know or there’s no incentive for doing so.

I’m not eliminating problem ranking but rather shifting it to the Solution Interviews. Problem interviews are more about discovery or hypotheses generation while solution interviews are more about hypotheses validation. While I understand your desire for quantitative metrics, I find they are better incorporated in the second interview.