Having the project team and risk management team would provide the ability to assess the risks associated with the project better and having a good overall sense of the project would allow the team to predict the outcomes/risks of certain changes/modifications that would impact the other areas of the project. But this would also lead to a pressure on the team for having to complete tasks within a given time frame making it tedious at times for time management.
Separate different teams as project management and risk management would mean a more dedicated team for evaluation of the risk probabilities which would be beneficial in cases when having the same project and risk management teams would not be able to determine a risk in certain cases. However, this would mean more time would be needed for the risk management team to assess the risks for any changes made apart from this having a separate project management and risk management teams would increase the overall cost of the project.