On my experience, what you actually get is your one or two "big brains" doing little to no work. They go to lots of conferences, are in a lot of meetings, derail almost all useful conversation, and maybe occasionally produce a UML diagram. The plebes responsible for actually building the system typically throw away the architect's design immediately, because while it's a beautiful, pure design, it doesn't take into account being deployed, running and being supported in the real world. The code monkeys then build a deeply flawed system, but it ships and works.
But at least the architect is great to have beers with during the Friday happy hour.
Skip the architects, make the monkeys do the design. Have them vet it with each other, preferably in a formal setting with your entire engineering team. Everyone codes, and everyone architects.