Actually your picture of 10/90 is probably more accurate than my 1/100 developers, I think that may have been quite an exageration, what is important in a project is that the most senior people coach their colleagues and take responsibility for creating something they can feel proud about.

I suppose an excellent developer is something special to the project. But having a few good ones instead can also get the job done quite well. And perhaps some of the good ones might become excellent in some time.