You only need an architect if you have a disfunctional team. Any reasonable group of developers should have the skills to address any issues that need to be addressed on a project. With more people thinking about the design more problems are likely to be thought about in the early stages.

This will also mean the team has more personal investment in the project and a greater understanding of the requirements. But spreading knowledge around the team your also reducing the truck number as know single person is the "holder of the vision".

What is probably required is a chairman, someone who will make sure that everyone is picking up all the lose ends and that meeting are run in an efficitent manner, rather than becoming talking shops. This role however requires no technical or domain skills just the ability to deal with people.