A work team should consist of three members, in my opinion. More could mean that one of the members would work much less than his classmates.
One of the members will become the leader – this is natural and logical, and experience says so.
They should deliver what each one is going to carry out.
When presenting their work to the rest of the class one should be the main speaker, every one of them should say something though. / Photo from: www jsc ac uk