Is enterprise architecture should include blueprints of system architecture?

While paying a visit to one of my colleague we have that argument. He argues that EA just map the current system architecture and pave the way for complete coverage of the enterprise needs by IT. From his point of view EA should not contained any system architecture blueprint, any system should be set up it own architecture.

I use to create pretty detailed system architecture blueprints. As I see it without blueprints it is much more difficult to governance the chosen architecture. Preferring one architecture on another is due to business and information architecture. So without architecture blueprints, which contain architecture patterns suiting business and information architecture, how can you enforce the right architecture for your organization..