Because in 2242 civilian quarters were everywhere.
And they don't needed APA for "dealing with radiation fluxes", for example, Chris is standing without APA in Navarro and technicians too. They just wanted some extra protection for places like Maripoas, but they could leave their places with classic power armors.
Your version is possible, mine too, (ofc. your more) I really don't see sense in debating about that one fact.
Both confirmed that Enclave lost most of manpower.