"[Y]ou trade off the benefits of seamless integration against the additional effort of coordination and communication." #readingToday

To sum up these guidelines, there is a range of strategies for unifying or integrating models. In general terms, you will trade off the benefits of seamless integration of functionality against the additional effort of coordination and communication. You trade more independent action against smoother communication. More ambitious unification requires control over the design of the subsystems involved.

Domain-Driven Design, Eric Evans