When active in a nice market people tend to avoid working with other people in the same niche. One is afraid of losing possible customers to the others.
In most cases it is much better to do the opposite and connect with as many active people in your field as possible.
I use an example from our austrian hip hop scene to show why:
There is a loose group of dancers that are responsible for doing a ton of projects, despite the fact that they are not in the same crew. Under different leadership they are doing event management, theater productions, movies, commercial shows, fashion labels and music production. The advantage is that everyone has an experienced workforce and at the same time more work during the year. All of this would not be happening if we avoided each other.