On any project you take part in, your main goal should be to contribute to and keep reinforcing the team spirit.
It doesn't always work, some colleagues aren't such a great match. But it's not enough to have objectives and to reach them if the team isn't growing as well.
Do all decisions considering the team as a whole. It's OK to let a star employee go if he doesn't fit in the team. When you're looking for new blood, run it past your team too.