I don't believe identifying a chief architect in Step 1 will be an issue, but pulling together the team of trained EA architects might be. I would imagine that, specifically, Steps 2 and 3 of Phase I would be the most challenging for VUSD. Actually, "challenging" isn't quite the right word. I believe the cooperation, vision, and mindset of department leadership is in place to allow EA to be successful; these steps will simply require the most investment of learning, time, and the creation and implementation of some new processes and habits. With the current way the various departments operate, establishing implementation methodology, EA governance and links to all management processes would require total teamwork and re-mapping of how things are done. I wouldn't anticipate buy-in to be an issue.
I am not sure what would make these Phase I activities more successful, except team-building, with district visioning at the core, and much information and rationale for the reorganization of how the district would operate. The stakeholders not familiar with EA would have much learning to do in order to adopt and implement a new way of organizing, planning, decision-making, and leading. Our IT director confirmed for me that VUSD's current architecture is the Blueprint (LCAP), which contains the eight strategies to be addressed, with allocated funding linked to each strategy. It took some EA mindset for district leadership to create and agree upon the eight strategies, so the next jump to EA implementation shouldn't be too difficult.
Bernard, S. A. (2012). An introduction to enterprise architecture.