First off I hate the phrase "Rockstar dev" because it gives the impression that someone can be successful without the support of the team, which is wrong.

Second, I hear this extremely often: Rockstar devs don't like to mentor, Rockstar devs don't like to write documentation, Rockstar devs don't like to write tests.

At what point do you need to reevaluate your definition of a rockstar dev?

The hiring filter is a powerful thing. It allows you to find very special people if you know how to look. It's also a feedback loop. Getting momentum with a program like this is the hardest part. Once it's going it practically self sustains. The biggest part of your role becomes quickly firing any mistakes.