A single mediocre hire in the first five will often in fact kill a startup.
You have to find a small market in which you can get a monopoly and then quickly expand.
Another way of looking at this, is that the best companies are almost always mission oriented.
For early employees you want people that have somewhat of a risk-taking attitude.
To get the very best people- they have a lot of great options, and so it can easily take a year to recruit someone.
The track record for founders that don't already know each other is really bad.