A few things would need to happen for there to be a good group of 2-5 over time:
There needs to be a clear goal or specific area
There needs to be several people who are very excited about working primarily on that goal for a long period of time
These people need to be very strong (to get funding)
These people must enjoy working with other people
These people must enjoy and be helped by working with each other
There probably should be at least one person who is willing to do managerial/operational duties, and is a good fit for it
A few things would need to happen for there to be a good group of 2-5 over time:
There needs to be a clear goal or specific area
There needs to be several people who are very excited about working primarily on that goal for a long period of time
These people need to be very strong (to get funding)
These people must enjoy working with other people
These people must enjoy and be helped by working with each other
There probably should be at least one person who is willing to do managerial/operational duties, and is a good fit for it