Not everyone can be a star, and there are many people who do just fine not being a star. They don’t crave the limelight, they don’t particularly want the attention, they just do a good, solid job and are happy that you thank them for doing just that.
These kind of people are essentially your grunts, the engine-house of your team. These are the guys that deliver stuff for you, day-in, day-out. You need them on your team.
If you have a team full of experts and stars; let’s call them Prima-Donnas, you will spend all your time massaging their egos, making up for their shortcomings, apologising to people they’ve annoyed or upset and stopping fights between them. They’ll take up a lot of your valuable time.
While you absolutely do need both in your team, you need to watch out. If you want your team to deliver, and not just postulate and come up with whizzy ideas, you would be well placed to make sure you have a high Grunt to Prima-Donna ratio.