With the Enterprise Architect comes the authority to lead. You don't need admin access so much as you need to cultivate loyal, capable followers from the SA's that you are leading. They should be the implementers of your architectural designs.
I do agree with the poster that you may need user level access to servers and/or the capability to configure/build different software in userspace before deploying it at a system level.
But Enterprise Architect is a leadership role mainly. From your explanation, you've been trying to lead and influence decisions all along, now they're giving you the authority to do so. Seize the opportunity!