Vernon Vaughn

Stated another way, when we are discussing a legacy system there are probably some, even many, logical domain models that exist inside that one legacy system.

Treating the logical Subdomains as such helps us grapple with the complexity of large systems. This makes a lot of sense because it allows us to treat the problem space as if it had been developed using DDD and multiple Bounded Contexts.

we can determine the Subdomains that are more valuable to the business and necessary for our project, and those that can be relegated to lesser status