Create an Architect role to guide the product
Create an Architect role as an embodiment of the architectural principles that define an architectural style for the project, and of the broad domain expertise that legitimizes such a style.
There needs to be some level of architectural vision. While some domain expertise is distributed through the ranks of the development team (DomainExpertiseInRoles), the system view -- and in particular, the design principles that create a common culture for dialogue and construction -- usually benefit from the conceptual integrity we associate with a single mind or small group.
While ArchitectureTeam deals with establishing the group where necessary, the Architect role deals with plugging architects in to the ongoing information flow. Having an Architect role also allows the individual architect to work in other roles, see ArchitectAlsoImplements.