Implementing a Hub-and-Spoke multi-org strategy by consolidating customer data in a single org, which will be the master of customer data, and using integration strategies to let the LOBs orgs read and write from it is one of the options an architect can recommend to accomplish the customer 360-degree view. This way, the architect can ensure that there is a single source of truth for the customer data, and that the data is consistent and synchronized across the different orgs. Implementing a Single Package multi-org strategy by developing and deploying to all orgs a managed package which reads and consolidates customer 360-degree view from the different orgs is another option an architect can recommend, as it allows the architect to create a reusable and scalable solution that can provide a unified view of the customer data from multiple sources.
Implementing a Complete Graph multi-org strategy or migrating from multi-org to single-org strategy are not feasible or optimal options, as they can introduce complexity, cost, or risk to the architecture.