Even if this was the origin of the term, it still doesn't make sense because the best engineers can solve problems the worst would never be able to do so. The difference between the best and worst is much more than 10x the worst. Maybe the worst who meets certain minimums at a company, but then the best would also be limited by those willing to work for what the company pays, and I hypothesis that the minimums of the lower bound and the maximums of the upper bound are correlated.
It sounds like you disagree with the concept of a 10x engineer then. In which case you should avoid using the term, rather than making up a new definition.
Concepts and words change meaning and sometimes we all need to accept that the popular meaning is not the definition we use.
This is especially common when dealing with historical or academic definitions versus common modern usage. "Evolution" particularly annoys me.
You should avoid using the term, rather than using a definition at odds with common usage. Your usage is confusing - and that is why you are getting push-back.
The definition you have given is nonsensical - it can't be consistent over time or between companies because it depends on finding a minimum in a group. And a value that is strongly dependent on the worst developer is useless because it mostly measures how bad the worst developer is - it doesn't say anything about how good the best developer is.
