Many of the most successful dance teams and crews that you see on television and in the dance industry are self assembled. A group of dancers may decide they want to form as a crew or a choreographer may bring a group of friends together that have similar views and interests when it comes to dancing.
One reason why such crews can be so successful is because many of the members already know each other. There is already a family like bond between the members and because they believe in what they are doing, they are prepared to work hard for it.
This is in contrast to working for a choreographer who they may not know very well that has put different dancers together. This can work too though it is often a challenge to get them to bond in the same way.
Groups that comprise of friends often spend time with each other away from shows and rehearsals. They may eat together, play games together, belt out family songs together and spend a lot of time together in general.