I think you can actually find the above level of developer - what many would classify a 'unicorn' - in approximately 1-2% of the workforce.

That doesn't mean they understand your business or products, know how to work well with other individuals, etc. There are a lot of other factors beyond just the productivity angle.

Now, the above developer also with the ability to fundamentally understand the business, as well as interact with all of the key people while performing said productivity stunts on a consistent basis... I think you are getting into the .1-.01% range.