I doubt Commercial Developers require such deals, because they earn a living. By earning a living, they can concentrate all their focus, talent, and time to the end product. We Independent Game Developers operate on a completely different development model, mostly based on Spare Volunteered Time and Low Budgets.
For these reasons, Development Teams in the community should Unite. However, as each Team desires to focus on their own game. This creates several management issues. In my opinion, Teams unite with intent to utilize the same subsystems & resources so that progression is made on multiple projects.