I'd invert this: why would a man-only team ever be a desirable situation? Normally if you have enough people, you should get fairly close to common ratio in numbers. If you end up with men only (or any X-only), it may be an indicator that there's something unhealthy about the company culture.

Following from that, it may be in your interest as a hiring person to bootstrap some diversity to remove that "unhealthy" idea early on.