One of the frustrating aspects of being an architect is knowing that there is a particular approach or technology that will help the Teams but also facing resistance from the teams in actually implementing that idea. Through a collaborative approach you will find there is help in getting some of these ideas to move. This is, in fact, one of those places where there is a significant benefit to having a large scale organization to work with.
In my early career as an agilist for a product development shop, we knew there was a benefit to doing test driven development but for a number of reasons (feature pressure, concern of the unknown, disbelief in the approach, …) we were unable to get teams to really bring the practice into their world. No amount of presentation, cajoling, threats made any kind of impact. Then I found a team that had actually done it, and were very pleased with the results. We had that team talk about their experiences and suddenly all kinds of teams were now adopting the practice.
It turns out that, no surprise, people listen more to the peers than anyone else. And in a large organization there is probably someone who has tried whatever practice or technology you are interested in working. Architects who are open to these experiences and work directly with teams are best positioned to leverage these peer effects.