Hiring the best engineers, technically-wise, is a good thing but it's not enough. In my experience it's better to hire somebody with a previous experience in the domain. Somebody that already built something similar or related. Those engineers will ask the right questions, make the customer think about the system in the right way, not lose time on worthless details. Even if the implementation is not shiny it will be working. It beats shiny but misguided. And if you can find great engineers with great skills, that's even better.